Microcephaly-lymphedema-chorioretinal dysplasia: a unique genetic syndrome with variable expression and possible characteristic facial appearance.

We report on a follow-up examination of a family with microcephaly and lymphedema. The finding of chorioretinal dysplasia with variable visual deficit in multiple relatives, which was not previously discovered, supports the concept of microcephaly, lymphedema, and chorioretinopathy as being a single autosomal dominant genetic entity with variable expression. We recommend that fundoscopic examination be performed in all patients with microcephaly with or without lymphedema.

Pathologic findings in pregnancies with unexplained increases in midtrimester maternal serum human chorionic gonadotropin levels.

Second trimester maternal serum human chorionic gonadotropin (MShCG) levels are commonly obtained as part of a screening protocol for chromosomal anomalies. Approximately 4% to 6% of patients have elevated hCG levels for gestational age, and this test has been reported to identify a group at risk for pregnancy complications. We ascertained 24 patients with unexplained elevated MShCG levels and available placental pathology among 5,790 deliveries during a 58-week period and compared them with 48 controls with normal MShCG levels delivering during the same period.

Cytogenetic and molecular genetic characterization of trisomy 20 mosaicism in fetal blood and tissues.

We report a case of mosaic trisomy 20, the most common autosomal mosaicism identified in amniocytes, ascertained in a woman referred for amniocentesis because of abnormal ultrasound at 18.1 weeks' gestation which revealed short femurs and nuchal thickening. Metaphase analysis of 98 clones revealed 47,XY, +20 in 96 cells (98 per cent).

Risk-based prenatal screening for trisomy 18 using alpha-fetoprotein, unconjugated oestriol and human chorionic gonadotropin.

Nine centres collaborated to examine the feasibility of a screening method for trisomy 18 that was based on assigning individual risk, using a combination of maternal age and measurements of alpha-fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotropin (hCG). Second-trimester measurements of these analytes were obtained from 94 trisomy 18 pregnancies. In the 89 pregnancies without an associated open defect, the median levels for AFP, uE3, and hCG were 0.

Partial X chromosome trisomy with functional disomy of Xp due to failure of X inactivation.

A 5-month-old girl with mild phenotypic abnormalities, developmental delay, and seizures was found to have the de novo karyotype 46,XX,-13,+der(13)t(X;13)(p21.2;p11.1).