Visual evoked potentials in Prader-Willi syndrome.

Oculocutaneous, electrophysiological, and cytogenetic factors were evaluated in 14 patients with Prader-Willi syndrome and in three controls, two albinos and a normal observer. In a substantial number of PW patients chromosomal anomalies, particularly deletions of the long arm of chromosome 15 as well as hypopigmentation of hair, skin, and eye have been identified. In the genetic condition of albinism, hypopigmentation related to neural ectoderm derivatives is associated with reduced visual acuity, foveal hypoplasia, and aberrant retinogeniculocortical projections.

A patient with an interstitial deletion of the short arm of chromosome 6.

The clinical history and subsequent progress of a child with an interstitial deletion in the short arm of chromosome 6 is described. This abnormality coupled with a reduced Hageman factor (Factor XII) led to an earlier publication which suggested that this gene was localized to the breakpoint region involved. A review of similar phenotypes from the literature is presented.

The role of ultrasound in the early diagnosis of fetal structural defects following maternal anticonvulsant therapy.

A total of 162 pregnant subjects using anticonvulsant drugs were examined for fetal congenital defects over a period of five years. In 138 of these subjects, alpha-feto-protein (AFP) levels were determined in amniotic fluid at 16 weeks of gestation to rule out spina bifida. In all instances, a fetal anomaly scan was performed between 18 and 20 weeks of gestation.