Weaver Syndrome: A Rare Cause of Neonatal Macrosomia and Dysmorphism. A Case Report.

Weaver syndrome is a rare genetic disorder characterized by abnormally excessive growth both in utero and postnatally. It is associated with a mutation in the EZH2 gene, which leads to accelerated bone development and other clinical manifestations such as macrocephaly, a characteristic dysmorphic facial appearance, hypotonia, and skeletal abnormalities. We report the case of a newborn, admitted for the management of Weaver syndrome diagnosed postnatally. The newborn, female, aged 1 day, was born at 38 weeks and 4 days of gestation through cesarean section, from a nonconsanguineous marriage. Her weight was 8200g (+8.7 SD), Apgar scores were 7/10 and 8/10. Clinical examination showed normal skin and mucosal coloring, eupneic, axial hypotonia, normal cardio-pulmonary auscultation, patent choanae and esophagus, height 68 cm (+10.12 SD), head circumference 40 cm (+6.01 SD). Facial dysmorphia included a broad forehead, hypertelorism, epicanthus, wide and prominent nose, long philtrum, retrognathia, wide ears with low insertion, scaphocephaly with macrocrania. Other findings included pectus excavatum, long and narrow thorax, lumbar scoliosis, umbilical hernia, spina bifida occulta, limited elbow and knee extension, camptodactyly of the 5th left toe, hollow feet, generalized skin hyperlaxity, mild skin jaundice, and weak, hoarse crying. X-ray of the left-hand revealed bone age of 2 years and 8 months. Abdominal ultrasound revealed vesicular microlithiasis. Cerebrospinal MRI showed hypotrophy of the corpus callosum, spina bifida occulta, lumbar scoliosis, and reduced height between the frontal scale and base of the skull. Infectious, renal, hepatic, metabolic, hormonal, and thyroid assessments were normal. The newborn was discharged on day 9 of life. The neurological prognosis is poor, marked by intellectual deficit and predisposition to cancers. Early diagnosis is essential for multidisciplinary management and genetic counseling.