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DOI: 10.1055/s-0045-1814752
Epidemiology of Congenital Upper Limb Anomalies in a Single Center: An Ambispective Study
Authors
Abstract
Background
Congenital upper limb anomalies (CULA) are common, but the actual magnitude of the problem within the community remains undetermined due to a lack of a registry system. Our study aimed to determine the epidemiology of CULA, its syndromic associations with other systems, to identify and categorize upper limb anomalies according to the International Federation of Societies for Surgery of the Hand (IFSSH) classification, to study the inheritance pattern of the disease, and to investigate the association of risk factors during the antenatal period.
Materials and Methods
This ambispective study was conducted at a tertiary care center from January 2022 to July 2024. Exclusion criteria included stillbirths, vascular malformations, congenital peripheral nerve disorders, and birth brachial plexus injuries. Comprehensive demographics, antenatal, perinatal, and postnatal histories, as well as family pedigrees, were documented. Each CULA case was classified according to the IFSSH guidelines, and statistical analysis was performed using Stata 18.0.
Results
There were 148 cases, with 5 dropouts, with a mean age of presentation being approximately 7 years, with approximately 58% males and approximately 42% females. The ratio of bilateral:right:left was 3.8:1.7:1. The most common non-hand involvement was in the foot, with the ratio of bilateral:right:left being 13.4:4.5:1. The mean birth weight was 2.75 kg, and the mothers' mean age at the time of birth was 26 years. There were three cases born to a consanguineously married couple, and four cases were detected on ultrasonography, with no significant correlation. There was positive familial correlation in IFSSH II, III, and VI categories, with p-values of 0.037, 0.001, and 0.026, respectively. The most common occurrence was seen in the IFSSH II category (98 cases) and the least in the IFSSH VI category (7 cases).
Conclusion
A substantial gap exists in the literature regarding the epidemiology and registry systems for CULA, rendering the full extent of the issue within communities ambiguous. However, IFSSH II is the most common anomaly with a varying pattern. Positive family history is commonly observed in IFSSH II, III, and VI groups, and syndromic associations are more prevalent in groups I and VII.
Keywords
congenital upper limb anomalies - congenital hand anomalies - CULA - IFSSH - epidemiology of congenital handIntroduction
Congenital anomalies of the upper limb are common and difficult to diagnose and treat due to varying patterns. The actual incidence, pattern, and distribution among the population are either missed or misdiagnosed. Upper extremity anomaly is seen in approximately 10% of children presenting with congenital anomalies.[1] According to various studies, the prevalence varies from 4.9 to 13 per 10,000 live births.[2] [3]
There is a paucity of literature regarding the epidemiology due to a lack of registry systems to identify congenital upper limb anomalies (CULA). Therefore, the actual burden of the problem in the community remains unknown. There have been nationwide studies conducted to assess the magnitude of the problem, classification of congenital hand differences, treatment modalities, and quality of life in children in different parts of the world.[4] [5]
Our study aimed to determine the epidemiology of CULA in a single tertiary-level center and its syndromic associations with other systems. The secondary objective was to identify and categorize upper limb anomalies according to the International Federation of Societies for Surgery of the Hand (IFSSH) classification, to study the inheritance pattern of the disease, to analyze the syndromic associations of other body parts, and to investigate the association of risk factors during the antenatal period. This study aims to provide a comprehensive overview of the epidemiology of CULA, offering valuable insights for health care professionals, researchers, and policymakers.
Materials and Methods
This was an ambispective study conducted at a tertiary care center from January 2022 to July 2024. All patients who visited our outdoor patient department directly or were referred cases from other departments with CULA were included in the prospective evaluation. All retrospective data were retrieved from the hospital's medical records and confirmed by photographs available for each patient or during follow-up of those operated patients. We excluded stillbirth, patients with vascular malformation of the upper limb, congenital peripheral nerve disorders, and birth brachial plexus injury. Apart from the patients' details, family history with pedigree was noted and documented, and each patient of CULA was classified according to the IFSSH classification (expanded version of the classification adopted by the congenital committee of the IFSSH).[5] All patients with positive family history and with syndromic features were sent to the Department of Genetics for evaluation and genetic counselling of the parents.
The entire dataset entered in an Excel sheet was statistically analyzed using Stata 18.0 on Windows. The data on categorical variables were represented as n (percentage of cases), and the data on continuous variables were represented as mean and standard deviation (SD). An independent t-test and the Mann–Whitney U test were used. The intragroup statistical comparison of the distribution of categorical variables was Fisher's exact probability test.
Results
Out of 148 cases, there were 5 dropouts with a mean age of presentation being approximately 7 years, with approximately 58% males (n = 83) and approximately 42% females (n = 60). The retrospective cases included 25 cases out of 148. Gender distribution based on IFSSH classification was not significant ([Fig. 1]). We catered to 10 neighboring states around the national capital, having a male preponderance. The ratio of bilateral:right:left was 3.8:1.7:1. In bilateral cases, there were 45 males and 35 females with p-values of 0.03 and 0.04 in IFSSH IV and V ([Fig. 2]). The most common non-hand involvement was seen in the foot, with a ratio of bilateral:left:right being 13.4:4.5:1. Bilateral foot involvement was the most common presentation in 32 cases, with female preponderance with p-values of 0.001, 0.018, 0.005, and 0.004 in IFSSH III, V, VI, and VII, respectively ([Fig. 3]).
The mean ± SD of birth weight was 2.75 ± 0.64 kg, showing moderate variability in birth weight ([Fig. 4]), with the average weight of females being 2.61 kg and males being 2.86 kg. The minimum birth weight was 1 kg in a preterm neonate, and the maximum birth weight was 4.5 kg in a neonate born to a diabetic mother. The mean age of mothers at the time of birth was 26 years, with 65.3% born out of normal vaginal delivery and 34.65% born out of lower segment cesarean section (LSCS). Out of nine preterm deliveries, two were vaginal, and seven were by LSCS. Nineteen cases had a neonatal intensive care unit (NICU) stay. All were immunized to date.
Firstborn children affected by CULA were 46.8%. Only three children were born to a consanguineously married couple, with one case of left-hand hypoplastic postaxial polydactyly with bilateral foot postaxial polydactyly, having a positive family history in a first-degree relative. The other two cases were bilateral hand and foot simple complete syndactyly, and right hand and bilateral foot constriction ring syndrome (CRS). There was no significant correlation for consanguinity among the IFSSH category ([Fig. 5]). There were 25 cases (∼19%) with positive family pedigree, having a more common presentation among first-degree relatives with female preponderance. There was a positive correlation in IFSSH II, III, and VI categories with p-values of 0.037, 0.001, and 0.026, respectively ([Fig. 6]).
Due to recall bias by the mothers, a detailed history of gross and fine motor skills could not be recorded. We could not establish a causal factor during the period of organogenesis and its correlation to CULA, as our sample size was small. Only four cases (∼3%) were detected on antenatal sonography with limitations. The findings were based on recall by parents or the ultrasound reports they had at the time of examination, which were mostly done at other places. In a case of CRS, the antenatal sonography missed hand findings, and in another case of twin pregnancy, acardia of the fetus was picked up.
There was an overlapping spectrum of cases in IFSSH types I and VIII ([Tables 1] and [2]). The most common occurrence was seen in the IFSSH II category with 98 cases, and the least in the IFSSH IV category with only 7 cases ([Tables 3] and [4]). We represented the IFSSH II to VI categories into several variables, and the count of each variable was taken based on the involvement of webspace, digit, or palm ([Tables 3] [4] [5] [6] [7]).
Abbreviation: IFSSH, International Federation of Societies for Surgery of the Hand.
IFSSH I had cleft hand as the most common presentation, followed by radial club hand.
Abbreviations: DIPJ, distal inter-phalangeal joint; IFSSH, International Federation of Societies for Surgery of the Hand; L IF, left index finger; L MF, left middle finger; L RF, left ring finger; L Th, left thumb; PIPJ, proximal inter-phalangeal joint; R IF, right index finger; R Th, right thumb; WS, web space.
Abbreviations: IFSSH, International Federation of Societies for Surgery of the Hand; L IF, left index finger; L MF, left middle finger; L RF, left ring finger; L Th, left thumb; R IF, right index finger; R Th, right thumb.
Abbreviations: IFSSH, International Federation of Societies for Surgery of the Hand; L IF, left index finger; L MF, left middle finger; L RF, left ring finger; L Th, left thumb; R IF, right index finger; R Th, right thumb.
Abbreviations: IFSSH, International Federation of Societies for Surgery of the Hand; L IF, left index finger; L MF, left middle finger; L RF, left ring finger; L Th, left thumb; R IF, right index finger; R Th, right thumb.
Abbreviations: IFSSH, International Federation of Societies for Surgery of the Hand; L IF, left index finger; L MF, left middle finger; L RF, left ring finger; L Th, left thumb; R IF, right index finger; PCT, Pattterson classification type; R Th, right thumb.
Abbreviations: IFSSH, International Federation of Societies for Surgery of the Hand.
Discussion
Total population-based studies on CULA exist in different countries, with few major studies maintaining their registry.[6] India lacks a unified system of registry on CULA.
There were 58% males and 42% females. The various studies reported incidence of CULA has been more common in boys than in girls. In a study of the epidemiology of CULA in a Midwest United States population, Goldfarb et al reported that 51% of the participants were males and 49% were females, based on an assessment using the Oberg- Manske- Tonkin (OMT) classification, which is comparable.[7]
The average age of presentation was 84.5 months (∼7 years) with a wide range of 40 to 468 months, with an SD of 90.49 months. This was in close approximation with the study done by Abulezz et al, which was 6 years.[8] The delay in presentation is attributed to low socioeconomic status, lack of education, and awareness.
Bilateral involvement of the upper limb was more common in our study, which coincides with the study by Mody et al.[9]
We encountered lower limb anomalies being more commonly associated anomalies present with CULA in around 47 cases. Bilateral foot involvement was the most common presentation in 32 cases, with female preponderance. Similarly, in the epidemiological study of CULA by Ekblom et al, the most common non-hand anomalies were recorded in the lower limb, constituting 129 among 562 children.[10]
In a study on parental consanguinity in specific types of congenital anomalies by Rittler et al, there was a significant association with consanguinity.[11] But our study had only three children born out of a consanguineously married couple, with no significant correlation to the development of CULA. Mody et al also found that only four cases were born of consanguineous marriage.[9] However, various other studies found that there was a significant history of their parents having first-degree relatives in up to 79% of cases.[11]
The mean age of mothers at the time of conception was 26 years, which was almost the same as 24.7 years as found in the study by Mody et al.[9] There were 25 cases (∼19%) with positive family pedigree, having a more common presentation among first-degree relatives with female preponderance. The p-value was significant in IFSSH II, III, and VI categories, which showed a positive correlation between the occurrence of the anomalies and positive family history.[12] This is supported in a study done by Abulezz et al, which had 26 patients with positive family history out of a total of 64 patients.[8] A very low rate of diagnosing CULA during the antenatal period by ultrasonography (∼3%) was mainly because it was done by a different observer. There can be interobserver variance; thus, we recommend a prospective radiological examination before concluding on a low rate of ultrasound findings.
The most common anomaly in IFSSH I was central ray deficiency—cleft hand, with one syndromic case having ectrodactyly ectodermal dysplasia (EED). Our study had three cases with positive family history. This is in contrast to the study done by Ekblom et al, where they did not find any familial occurrence.[10]
Phocomelia is a rare presentation; we had two cases in our study. One patient in our study had amelia (absence of humerus) with a syndromic association. Such a case has already been reported previously by Froster and Baird (1990).[13] Both cases in our study did not have any drug exposure or familial occurrence, which is in contrast to the Finland population study on the description of the thalidomide tragedy.[14]
Failure of differentiation was the most frequent anomaly in our study. This is consistent with the majority of the population-based studies, but in contrast to studies done at Midwestern Center in the United States and Ludhiana (Punjab, India), where polydactyly was the most common in 21 cases with a p-value of 0.037 (<0.05), thus depicting the correlation between occurrence, followed by syndactyly, as stated by Mody et al.[7] [9] [15]
There was a positive family history, and the occurrence of syndactyly. A recent study by Zaib et al on understanding the genetic etiology of syndactyly states that inter- and intrafamilial phenotypic variability is relatively common.[16] Most cases of syndactyly occur as isolated limb disorders, but some may occur in combination with other anomalies like polydactyly, acrosyndactyly, brachysyndactyly, cleft hand, clinodactyly, or in conjunction with syndromes such as Apert syndrome, Poland's syndrome, or Pfeiffer syndrome, as encountered in our study.[16] Bilateral hand involvement was most common in our study, with a male-to-female ratio of 1.6:1, and the left third webspace exhibited the most complete simple syndactyly cases, which has also been reported by Abulezz et al in their study.[8] However, firm conclusions regarding the percentage could not be drawn due to the overlap of IFSSH II with IFSSH V category cases and a small sample size. Furthermore, our findings contrast with those of Abulezz et al, as they report female preponderance, which can be attributed to the relatively higher percentage of females in their study and the small number of cases.[8]
Duplication encompassing polydactyly was the next most common presentation in our study. There was a significant correlation between positive family history and the occurrence of duplication cases in our study. This has been recently studied by Zaib et al in their paper on understanding the genetic etiology of syndactyly cases, which states that different types of duplication, as well as missense and deletion variations in HOXD13, cause typical synpolydactyly.[16] Postaxial polydactyly and its variation, having complete or incomplete fusion with its duplicated part, which is either a totally formed digit or hypoplastic, was also included in our study. This is in contrast to the study done by Chen et al, as their population had preaxial polydactyly as the most common presentation employing Wassel classification, types IV and II were the most common.[17] However, in our study, Wassel classification II and IV were the most common among preaxial polydactyly cases, but they stood next in the list after postaxial polydactyly cases.
Macrodactyly constituted the least occurring anomaly in our study, with a total of seven cases. All cases had no familial history, which was consistent with the study done in China on 90 macrodactyly cases by Wu et al.[18] They also stated no history of fever, trauma, or special complications during pregnancy. But our study had one case whose mother was on antipsychotic drugs till the first trimester of her pregnancy. However, macrodactyly is generally believed to be related to genetic (PIK3CA) or developmental abnormalities rather than drug exposure.[19]
The cases of brachydactyly or hypoplasia were more in number due to the overlapping of IFSSH II and V categories, sharing both the features.
CRS was the next most common in our study. We had one case with a positive family history of having a similar complaint in his father, which showed a significant p-value in our study. But due to the small sample size, we cannot generalize this to the population. Rossillon et al, in their study on CRS report of 19 cases, stated a case with positive family history in the patient's brother suffering from hypospadias and cardiac malformation, but none related to CRS.[20] Torpin, in his study, has described the exogenous theory of CRS based on observation of the placenta.[21] We had two cases with a mother having a history of oligohydramnios. Most cases were products of first conception born to young mothers, in sync with a study by Rossillon et al.[20] Contrary to findings of Kino and Moses et al, who stated that the central digits are more often affected compared with extreme digits, our study had involvement of extreme digits also with less number of occurrences in the thumb.[22] [23]
IFSSH VII cases constitute heterogeneous anomalies ranging from phocomelia, Poland syndrome, Apert syndrome, EED, hemifacial microsomia, popliteal pterygium, to faciocardiomelic syndrome. However, there were three cases that had a positive family history in our study. Shi et al studied prenatal limb defects, stating high-risk factors and chromosomal abnormalities related to limb defects.[24] We had 12% of cases falling in this category, which was in sync with the Leung et al study in the Hong Kong population.[25]
Limitations
Since it is an ambispective study, a few retrospective data points were missing. The IFSSH classification still has some overlapping entities; thus, characterizing them into unique entities is at the author's discretion, which requires universalization. When multiple anomalies occurred in the same limb, it was not easy to select the primary or predominant anomaly type of anomaly. Thus, there was an overlap in the categorization under the IFSSH category. A clearer definition would be necessary to allow accurate classification and sensible comparisons between the incidences in different series. The recent adaptation of OMT classification by IFSSH might overcome these problems; however, we recommend a comparative study to see the actual accuracy of the different classification systems. Being a hospital-based epidemiological observation, selection bias is another limitation. A small sample size was also a limitation that can be overcome by a multicentric study.
Conclusion
A substantial gap exists in the literature regarding the epidemiology and registry systems for CULA, rendering the full extent of the issue within communities ambiguous. The most common incidence is found in IFSSH II, and the least in the IFSSH IV category. The bilateral site is more affected than the right, followed by the left. The most common non-hand anomaly was in the lower limb, usually bilateral, with a female preponderance. The positive correlation between the occurrence of the anomalies and positive family history is noted in IFSSH II, III, and VI categories. The most common syndromic features are found in IFSSH I and VII, with Apert and Poland syndrome being more common. The study provides comprehensive insights for health care professionals, researchers, and policymakers to make an early diagnosis and timely treatment of CULA; however, this also highlights the scope of a registry system to document all congenital hand anomalies in a geographic population.
Conflict of Interest
None declared.
Patients' Consent
Informed consent was obtained from all the participants of the study.
Ethical Approval
The study was approved for ethical clearance by AIIMS Institutional Ethical Committee with the approval number IECPG-439/26.05.2022, RT-34/30.06.2022.
Note
This paper was presented at APSICON 2025, and the only abstract was published in a special edition.
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References
- 1 Flatt AE. Classification and incidence. In: The Care of Congenital Hand Anomalies. 2nd ed.. St Louis, MO: Quality Medical Publishing; 1994: 466
- 2 Vasluian E, van der Sluis CK, van Essen AJ. et al. Birth prevalence for congenital limb defects in the northern Netherlands: A 30-year population-based study. BMC Musculoskelet Disord 2013; 14 (01) 323
- 3 Mano H, Fujiwara S, Takamura K. et al. Congenital limb deficiency in Japan: A cross-sectional nationwide survey on its epidemiology. BMC Musculoskelet Disord 2018; 19 (01) 262
- 4 Makhoul IR, Goldstein I, Smolkin T, Avrahami R, Sujov P. Congenital limb deficiencies in newborn infants: Prevalence, characteristics and prenatal diagnosis. Prenat Diagn 2003; 23 (03) 198-200
- 5 Swanson AB. A classification for congenital limb malformations. J Hand Surg Am 1976; 1 (01) 8-22
- 6 Shin YH, Baek GH, Kim YJ, Kim MJ, Kim JK. Epidemiology of congenital upper limb anomalies in Korea: A nationwide population-based study. PLoS ONE 2021; 16 (03) e0248105
- 7 Goldfarb CA, Ezaki M, Wall LB, Lam WL, Oberg KC. The Oberg-Manske-Tonkin (OMT) classification of congenital upper extremities: Update for 2020. J Hand Surg Am 2020; 45 (06) 542-547
- 8 Abulezz T, Talaat M, Elsani A, Allam K. Congenital hand anomalies in Upper Egypt. Indian J Plast Surg 2016; 49 (02) 206-213
- 9 Mody NB, Srinivasan S, Thatte M. Cross-sectional study of epidemiology of congenital anomaly of the hand in a tertiary care centre in India over 1 year. Indian J Plast Surg 2016; 49 (03) 424-425
- 10 Ekblom AG, Laurell T, Arner M. Epidemiology of congenital upper limb anomalies in 562 children born in 1997 to 2007: A total population study from Stockholm, Sweden. J Hand Surg Am 2010; 35 (11) 1742-1754
- 11 Rittler M, Liascovich R, López-Camelo J, Castilla EE. Parental consanguinity in specific types of congenital anomalies. Am J Med Genet 2001; 102 (01) 36-43
- 12 Barik S, Pandita N, Paul S. et al. Prevalence of congenital limb defects in Uttarakhand state in India-A hospital-based retrospective cross-sectional study. Clin Epidemiol Glob Health 2021; 9: 99-103
- 13 Froster UG, Baird PA. Upper limb deficiencies and associated malformations: A population-based study. Am J Med Genet 1992; 44 (06) 767-781
- 14 Koskimies E. Congenital upper limb defects in Finland 1993–2005. J Hand Surg Am 2011; 36 (06) 1058-1065
- 15 Ghorpade N, Goyal N, John J. Prevalence of musculoskeletal abnormalities in newborn: A 10 years retrospective analysis of 10,674 neonates in Indian population at a tertiary care hospital. J Clin Neonatol 2015; 4 (02) 104-108
- 16 Zaib T, Rashid H, Khan H, Zhou X, Sun P. Recent advances in syndactyly: Basis, current status and future perspectives. Genes (Basel) 2022; 13 (05) 771
- 17 Chen Y, Knezevic V, Ervin V, Hutson R, Ward Y, Mackem S. Direct interaction with Hoxd proteins reverses Gli3-repressor function to promote digit formation downstream of Shh. Development 2004; 131 (10) 2339-2347
- 18 Wu J, Tian G, Ji Y, Higgins JP, Lee WPA. Clinical characteristics of 90 macrodactyly cases. J Hand Surg Am 2020; 45 (10) 982.e1-982.e5
- 19 Gazzin A, Leoni C, Viscogliosi G. et al; Italian Macrodactyly and PROS Association. Work-up and treatment strategies for individuals with PIK3CA-related disorders: A consensus of experts from the Scientific Committee of the Italian Macrodactyly and PROS Association. Genes (Basel) 2023; 14 (12) 2134
- 20 Rossillon D, Rombouts JJ, Verellen-Dumoulin C, Vanwijck R, Vincent A, de Coninck A. Congenital ring-constriction syndrome of the limbs; a report of 19 cases. Br J Plast Surg 1988; 41 (03) 270-277
- 21 Torpin R. Amniochorionic mesoblastic fibrous strings and amnionic bands: associated constricting fetal malformations or fetal death. Am J Obstet Gynecol 1965; 91 (01) 65-75
- 22 Kino Y. Clinical and experimental studies of the congenital constriction band syndrome, with an emphasis on its etiology. J Bone Joint Surg Am 1975; 57 (05) 636-643
- 23 Moses JM, Flatt AE, Cooper RR. Annular constricting bands. J Bone Joint Surg Am 1979; 61 (04) 562-565
- 24 Shi Y, Zhang B, Kong F, Li X. Prenatal limb defects: Epidemiologic characteristics and an epidemiologic analysis of risk factors. Medicine (Baltimore) 2018; 97 (29) e11471
- 25 Leung PC, Chan KM, Cheng JC. Congenital anomalies of the upper limb among the Chinese population in Hong Kong. J Hand Surg Am 1982; 7 (06) 563-565
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Publication History
Article published online:
03 February 2026
© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)
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References
- 1 Flatt AE. Classification and incidence. In: The Care of Congenital Hand Anomalies. 2nd ed.. St Louis, MO: Quality Medical Publishing; 1994: 466
- 2 Vasluian E, van der Sluis CK, van Essen AJ. et al. Birth prevalence for congenital limb defects in the northern Netherlands: A 30-year population-based study. BMC Musculoskelet Disord 2013; 14 (01) 323
- 3 Mano H, Fujiwara S, Takamura K. et al. Congenital limb deficiency in Japan: A cross-sectional nationwide survey on its epidemiology. BMC Musculoskelet Disord 2018; 19 (01) 262
- 4 Makhoul IR, Goldstein I, Smolkin T, Avrahami R, Sujov P. Congenital limb deficiencies in newborn infants: Prevalence, characteristics and prenatal diagnosis. Prenat Diagn 2003; 23 (03) 198-200
- 5 Swanson AB. A classification for congenital limb malformations. J Hand Surg Am 1976; 1 (01) 8-22
- 6 Shin YH, Baek GH, Kim YJ, Kim MJ, Kim JK. Epidemiology of congenital upper limb anomalies in Korea: A nationwide population-based study. PLoS ONE 2021; 16 (03) e0248105
- 7 Goldfarb CA, Ezaki M, Wall LB, Lam WL, Oberg KC. The Oberg-Manske-Tonkin (OMT) classification of congenital upper extremities: Update for 2020. J Hand Surg Am 2020; 45 (06) 542-547
- 8 Abulezz T, Talaat M, Elsani A, Allam K. Congenital hand anomalies in Upper Egypt. Indian J Plast Surg 2016; 49 (02) 206-213
- 9 Mody NB, Srinivasan S, Thatte M. Cross-sectional study of epidemiology of congenital anomaly of the hand in a tertiary care centre in India over 1 year. Indian J Plast Surg 2016; 49 (03) 424-425
- 10 Ekblom AG, Laurell T, Arner M. Epidemiology of congenital upper limb anomalies in 562 children born in 1997 to 2007: A total population study from Stockholm, Sweden. J Hand Surg Am 2010; 35 (11) 1742-1754
- 11 Rittler M, Liascovich R, López-Camelo J, Castilla EE. Parental consanguinity in specific types of congenital anomalies. Am J Med Genet 2001; 102 (01) 36-43
- 12 Barik S, Pandita N, Paul S. et al. Prevalence of congenital limb defects in Uttarakhand state in India-A hospital-based retrospective cross-sectional study. Clin Epidemiol Glob Health 2021; 9: 99-103
- 13 Froster UG, Baird PA. Upper limb deficiencies and associated malformations: A population-based study. Am J Med Genet 1992; 44 (06) 767-781
- 14 Koskimies E. Congenital upper limb defects in Finland 1993–2005. J Hand Surg Am 2011; 36 (06) 1058-1065
- 15 Ghorpade N, Goyal N, John J. Prevalence of musculoskeletal abnormalities in newborn: A 10 years retrospective analysis of 10,674 neonates in Indian population at a tertiary care hospital. J Clin Neonatol 2015; 4 (02) 104-108
- 16 Zaib T, Rashid H, Khan H, Zhou X, Sun P. Recent advances in syndactyly: Basis, current status and future perspectives. Genes (Basel) 2022; 13 (05) 771
- 17 Chen Y, Knezevic V, Ervin V, Hutson R, Ward Y, Mackem S. Direct interaction with Hoxd proteins reverses Gli3-repressor function to promote digit formation downstream of Shh. Development 2004; 131 (10) 2339-2347
- 18 Wu J, Tian G, Ji Y, Higgins JP, Lee WPA. Clinical characteristics of 90 macrodactyly cases. J Hand Surg Am 2020; 45 (10) 982.e1-982.e5
- 19 Gazzin A, Leoni C, Viscogliosi G. et al; Italian Macrodactyly and PROS Association. Work-up and treatment strategies for individuals with PIK3CA-related disorders: A consensus of experts from the Scientific Committee of the Italian Macrodactyly and PROS Association. Genes (Basel) 2023; 14 (12) 2134
- 20 Rossillon D, Rombouts JJ, Verellen-Dumoulin C, Vanwijck R, Vincent A, de Coninck A. Congenital ring-constriction syndrome of the limbs; a report of 19 cases. Br J Plast Surg 1988; 41 (03) 270-277
- 21 Torpin R. Amniochorionic mesoblastic fibrous strings and amnionic bands: associated constricting fetal malformations or fetal death. Am J Obstet Gynecol 1965; 91 (01) 65-75
- 22 Kino Y. Clinical and experimental studies of the congenital constriction band syndrome, with an emphasis on its etiology. J Bone Joint Surg Am 1975; 57 (05) 636-643
- 23 Moses JM, Flatt AE, Cooper RR. Annular constricting bands. J Bone Joint Surg Am 1979; 61 (04) 562-565
- 24 Shi Y, Zhang B, Kong F, Li X. Prenatal limb defects: Epidemiologic characteristics and an epidemiologic analysis of risk factors. Medicine (Baltimore) 2018; 97 (29) e11471
- 25 Leung PC, Chan KM, Cheng JC. Congenital anomalies of the upper limb among the Chinese population in Hong Kong. J Hand Surg Am 1982; 7 (06) 563-565