Xia-Gibbs syndrome (XGS): a case report

*Correspondence: [e-mail].

Abstract

Case Presentation: LDSA, 3 years old, born at term, weighing 3.080 g, 47 cm long, 34.5 cm head circumference, Apgar score 9/9. Cardiac alterations were suspected in the maternity ward, an echocardiogram showed a patent foramen ovale and a small persistence of ductus arteriosus. The parents noted global hypotonia 03 months, when started follow-up with Pediatric Neurologist. Congenital hypothyroidism and impacts due to malformations of the central nervous system were excluded. MRI shows a prominent left retrocerebellar subarachnoid space, with no clinical connotation, and a videoelectroencephalogram shows moments of gaze stoppage and hypoactivity, with no change in brain electrical activity. Child with global delay in neuropsychomotor development and suspected autism spectrum disorder, presented cephalic support at 6 months, sitting without support at 1 year and 1 month, at 3 years old stands up and walks with support, speech delay, speaks few words to date. On physical examination, she showed global hypotonia, hypertrichosis, frontal protuberance, sinopris, small nose, bluish sclera, megalocornia, mild micrognathia, small midface, posteriorly rotated ears, brachycephaly, partial Siamese folds. Evaluation carried out with Geneticist, karyotype study revealed 46, XX chromosomes, genetic microarrays were also normal. Ultimately, exome sequencing revealed the pathogenic Xia-Gibbs Syndrome (XGS), with de novo missense variants of the molecular picture. The patient's findings do not suggest intellectual disability associated with the BRPF1 gene and the main mechanism of the disease in the gene and by loss of function.

Discussion: The Xia-Gibbs syndrome (XGS) is an autosomal dominant disorder, that include in most affected individuals delayed motor milestones, severe or absent speech delay, moderate to severe cognitive impairment, global hypotonia, structural brain anomalies. It may also include sleep apnea, movement disorders (ataxia and bradykinesias), short stature, seizures, eye abnormalities (such as bluish sclera), autism spectrum disorder, scoliosis. The diagnosis of the Syndrome is established on a set of suggestive clinical findings associated with pathogenic germline variants in AHDC1, identified by molecular genetic testing.

Final Comments: It is essential to keep multidisciplinary follow-up of these patients, in order to stimulate and guarantee the greatest potential for neuropsychomotor development.

Publikationsverlauf

Artikel online veröffentlicht:
12. Mai 2025