*Centro Médico Profesional Rosancar. Barquisimeto, Estado Lara, Venezuela.
** Inner Vision Women's Ultrasound, Nashville, Tennessee, USA. Department of Obstetrics and Gynecology, University Hospital Brno, Masaryk University, Czech Republic.
Introduction
X-linked recessive form of congenital hydrocephalus is the most common of the inherited forms of hydrocephalus. The prevalence is 0.3 in 10,000. The affected male individuals usually show the whole spectrum of the findings:
- Severe hydrocephalus
- Adducted thumbs
- Spasticity
- Severe mental retardation
Hydrocephalus and position of the thumbs can be detected already prenatally. Prenatal diagnosis of this condition allows us to prepare the whole team of specialists who would take care of the neonate. The well-timed shunting of the cerebrospinal fluid is a very important part of the treatment of this condition.  Family history which shows a X-linked pattern of inheritance (affected male individuals) and clinical findings help us to diagnose this condition. Carrier testing and prenatal testing is available if there is a L1CAM disease-causing mutation identified in the family. Preimplantation genetic diagnosis is possible.
Case report
A 34-year-old patient G4P3 was referred to our unit at 23 weeks of gestation because of the ultrasound findings of a mild ventriculomegaly. She had a non-contributive family or personal history. Both her previous pregnancies were uneventful but the first baby died two days after delivery due to a severe hydrocephalus. All her babies were boys. We have seen the following images during the ultrasound scan. The congenital stenosis of aqueduct Sylvius was diagnosed postnatally based on the pathology examination.
Images1,2: Image 1 shows a mild dilatation of the third ventricle. Image 2 shows a dilatation of the lateral ventricle.