Hypotonia, Seizures, And Precocious Puberty

Clinical Features

Smith et al. (2008) reported 3 sibs, 2 boys and a girl, with a similar syndrome comprising hypotonia, seizures, and dysmorphic features. Two of the children had precocious puberty. At birth, all had severe hypotonia and abnormal facial features including brachycephaly, plagiocephaly, and prominent eyes. Other features included transverse palmar creases, folded toes, severe developmental delay, and onset of myoclonic and generalized seizures within the first 2 years of life. Variable features included preauricular tags and inverted nipples. One of the boys died unexpectedly at age 9 years. The other boy and the girl developed signs of precocious puberty at ages 7 and 5, respectively. Laboratory studies showed increased serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Smith et al. (2008) noted that some of the features were similar to that of Prader-Willi syndrome (176270), but none of the children had feeding problems or obesity. Extensive cytogenetic and metabolic studies did not show any abnormalities. Autosomal recessive inheritance was postulated.