Neu-Laxova Syndrome

Neu-Laxova syndrome (NLS) is a rare, multiple malformation syndrome characterised by severe intrauterine growth retardation (IUGR), severe microcephaly with a sloping forehead, severe ichthyosis (collodion baby type), and facial dysmorphism.

Epidemiology

About 60 cases of this syndrome have been reported from diverse ethnic backgrounds.

Clinical description

Severe central nervous system (CNS) defects are present: lissencephaly type III, hypoplastic cerebellum and brainstem, enlarged ventricles, and sometimes intracerebral calcifications, Dandy-Walker anomaly or agenesis of the corpus callosum. Facial features include severe proptosis with ectropion (giving the impression of missing eyelids), hypertelorism, micrognathia, flattened nose, and malformed ears. The lips are thick with a round, gaping mouth. Other inconstant malformations include abnormal limbs (contractures and, sometimes, radial ray defects), abnormal external genitalia, and arthrogryposis multiplex. Clinical features show significant intra and interfamilial variation.

Diagnostic methods

The diagnosis is easily made at birth on the basis of the clinical malformations. The histopathological findings include a triad of dermatological features (ichthyosis, massive fat with hypertrophy of fat cells, oedema), poor formation of the cortical bone, and central nervous system (CNS) anomalies.

Antenatal diagnosis

Routine ultrasonography (at 19 to 20 weeks of gestation) may show polyhydramnios, IUGR, hypoechogenic skeletal structures, microcephaly, prominent eyes, retrognathism, hypomobility with flexion deformities. It also shows massive swelling of the scalp, knee, elbow joints, hands and feet, giving the impression of absent digits. At risk pregnancies should be carefully monitored by ultrasonography: at 6-8 weeks for accurate dating, at 12-16 weeks for analysis of activefoetal limb movements, and at 16-24 weeks for the detection of facial and skeletal anomalies, IUGR and polyhydramnios.

Genetic counseling

The syndrome is transmitted in an autosomal recessive manner. Parents should be informed of a 25% recurrence rate in future offspring.

Prognosis

The prognosis is poor: affected newborns either are stillborn or die immediately after birth.