Smith-Lemli-Opitz syndrome in a female with a de novo, balanced translocation involving 7q32: probable disruption of an SLOS gene.

A 3-month-old infant girl had manifestations of the Smith-Lemli-Opitz syndrome (SLOS) including typical positional anomalies of the limbs, apparent Hirschsprung disease, cataracts, ptosis, anteverted nares, cleft of the posterior palate, small tongue, broad maxillary alveolar ridges, and abnormally low serum cholesterol levels. Chromosomal analysis showed a de novo balanced translocation interpreted as 46,XX,t(7;20)(q32.1;q13.2). We hypothesize that the translocation breakpoint in this case interrupts one SLOS allele and that the other allele at the same locus has a more subtle mutation that was inherited from the other parent. This case, as well as cytogenetic observations in other SLOS cases, suggests that SLOS could be due to autosomal recessive mutation at a gene in 7q32.

Angelman syndrome: clinical profile.

To further delineate the clinical and developmental features of Angelman syndrome, we collected data through three sources of information: (1) physical examinations; (2) laboratory data and family questionnaire data of affected individuals; and (3) literature review. The questionnaire data describes a generally normal prenatal and birth history. Feeding difficulties, developmental delay, or seizures were the presenting problems in all infants. The diagnosis of Angelman syndrome, however, was not made in any infant prior to 1 year of age. Except for seizures, no medical or surgical complication was common, although a variety of visual complaints or findings were common. Sixty percent of Angelman syndrome children had a cytogenetically demonstrated deletion of chromosome 15q11-q13. The individuals with and without a deletion could not be differentiated clinically. Diagnosis in early childhood is therefore difficult, and a high index of suspicion is recommended.