Congenital hydrocephalus in an Egyptian baby with trisomy 18: a case report

Trisomy 18 is the second most common autosomal trisomy after Down syndrome (trisomy 21). A variety of anomalies of the central nervous system are observed in cases of trisomy 18. The association between trisomy 18 and congenital hydrocephalus is very rare.

A 4-month-old male Egyptian baby boy was referred to Assiut University hospital for evaluation of his large-sized head. The initial clinical examination revealed facial dysmorphism including a prominent wide forehead, wide anterior fontanel, bushy eyebrows, synophrosis, small palpebral fissures, ocular hypertelorism, high arched palate, depressed nasal bridge, low-set ears, micrognathia, bilateral clenched hands with over lapping fingers, rocker-bottom feet and penile hypospadius. A computed tomography scan of the patient's head showed a dilatation of all the ventricular systems of the brain that suggested hydrocephalus. A chromosome analysis of his peripheral blood confirmed a trisomy of chromosome 18 (47, XX+18). The hydrocephalus was treated with a ventriculoperitoneal shunt because of the abnormal increase in his head circumference. He was discharged home on nasogastric feeds at the age of 5 months. Despite the advice of the medical team, his parents did not bring him for further follow up. He died at the age of 7 months due to a sudden cardiorespiratory arrest at home.

Microcephaly is not mandatory for the diagnosis of trisomy 18 syndrome because some cases of trisomy 18 can be associated with other anomalies of the central nervous system, including hydrocephalus. There is no proven explanation for this association, and the management of hydrocephalus in such a situation is not different from the usual course of management.