Case report: pontocerebellar hypoplasia type 1D

Case presentation: This report aims to describe the case of a patient with a rare diagnosis of type 1D pontocerebellar hypoplasia (PCH1D), resulting from the alteration of the EXOSC9 gene. G. T. S. D. S., male, 1 year and 2 months old, fruit of unplanned pregnancy of non-consanguineous parents. Prenatal care was complete. The patient was born by vaginal delivery without complications, with 36 weeks and 6 days of gestational age, and with the following measurements: height = 44.5 cm; weight = 2,660 kg; head circumference = 33.8 cm.

Discussion: At the age of 2 months, the first change arose and was noticed: look evered up fixedly. When started investigation: electroencephalogram, computed tomography of the skull and magnetic resonance imaging of the skull. All with unchanged results. Then, they consulted a geneticist, who requested the following tests: screening tests for inborn errors of metabolism. All with unchanged results. From the age of 3 months, he started rehabilitation and he showed improvement: he still did not present cephalic support, but he was able to rotate her neck. At the age of 6 months, he started with spasms, several per day. When started with valproic acid, but adverse reactions of drowsiness caused it to be suspended before 1 month of use; vigabatrin was introduced and, after 1 month, spasms ceased completely. Currently, the patient remains under specialized follow-up, and makes use of: vigabatrin 500 mg a day. At this time, a new MRI was also performed, which showed pontocerebellar hypoplasia, and received the result by the complete exome sequencing test: a homozygous EXOCS9 gene variant (NM_001034194.1: c.41T>C-p.Leu14Pro) From the age of 7 months, he stopped gaining weight, requiring follow-up with gastropediatrics and nutrology. Since then, he has needed gastrostomy to be able to receive a full diet.

Final comments: In addition to the present case, only 10 others were reported, with the same EXOCS9 gene variant (NM_001034194.1: c.41T>C-p.Leu14Pro), which represents 60% of the total reported cases of PCH1D. It is a severe autosomal recessive neurologic disorder characterized by severe hypotonia and a motor neuronopathy apparent, and also includes severely delayed gross motor development. The patients may present poor overall growth, contractures, eye movement abnormalities, respiratory insufficiency and feeding difficulties and epilepsy. The case shows the importance of molecular study for predicting prognosis and family guidance.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023