Perinatal imaging findings of inherited Sotos syndrome.

Abstract

Although most cases of Sotos syndrome are sporadic, familial cases have been described. In familial cases, the most likely mode of inheritance is autosomal dominant with variable expressivity. We present the perinatal imaging findings of an inherited case. This was the second pregnancy of a 32-year-old woman with Sotos syndrome. She had given birth to her first child with macrocephaly, ventriculomegaly, macrocisterna magna and neonatal death at 28 weeks' gestation. During this pregnancy, prenatal ultrasonography at 18 weeks' gestation showed only mild dilatation of lateral ventricles. The pregnancy was uneventful until 31 weeks' gestation when fetal macrocephaly, right hydronephrosis, and polyhydramnios began to develop. At 33 weeks' gestation, dilatation of the third ventricle and fetal overgrowth were obvious. At 34 weeks' gestation, macrodolichocephaly, hypoplasia of the corpus callosum, enlargement of the lateral ventricles with prominent occipital horns, and macrocisterna magna were noted. At 36 weeks' gestation, a male baby was delivered with macrodolichocephaly, frontal bossing and a facial gestalt of Sotos syndrome. Birth weight was 3822 g, length 55 cm, and occipitofrontal head circumference 41 cm (all > 97th centile). The magnetic resonance imaging (MRI) scans demonstrated enlargement of the lateral ventricles, the trigones, and the occipital horns, hypoplasia of the corpus callosum, a persistent cavum septum pellucidum and cavum vergae, and macrocisterna magna. Fetuses at risk for Sotos syndrome may present abnormal sonographic findings of the brain and the skull in association with overgrowth, unilateral hydronephrosis and polyhydramnios in the third trimester. Perinatal MRI studies aid in confirmation of the diagnosis.