E. Vamos

Congenital malformations in 10,000 consecutive births in a university hospital: Need for genetic counseling and prenatal diagnosis

Ten thousand children born consecutively in a university hospital were surveyed for the presence of major congenital malformations. About 2% (174) had a major congenital defect. Seventy-eight percent (135 of 174) of these malformations are associated with increased recurrence risk (greater than 1%), and 9% carry a high recurrence risk (greater than or equal to 10%). On the basis of the recurrence risk of 1% or higher and the feasibility of prenatal diagnosis, such a procedure should be considered in future pregnancies in 45% (79 of 174) of the mothers, especially inasmuch as 40% were primiparae younger than 36 years.

Two unrelated children with partial trisomy 1q and monosomy 6p, presenting with the phenotype of the Larsen syndrome

SummaryTwo unrelated children presented with similar clinical features (facial dysmorphism and multiple joint dislocations) suggesting the diagnosis of Larsen syndrome. Both carried an inherited unbalanced translocation resulting in partial trisomy 1q and partial monosomy 6p. Analysis of skin collagen from one of the probands disclosed a decreased α1/α2 chain ratio of collagen type I, increased thermal stability and increased hydroxylation of proline and lysine. The present findings suggest that, as a result of the chromosome rearrangements, both patients have a mutation on a gene involved in collagen production, located either on chromosome 1q or, more probably, on 6p. It is furthermore suggested that other cases of Larsen syndrome are the result of a similar mutation.

Alphafetoprotein (AFP), concanavalin A non-reactive AFP and specific acetylcholinesterase in amniotic fluid from pathological pregnancies. Predictive values for open spina bifida.

Alphafetoprotein (AFP) and concanavalin A non-reactive alphafetoprotein determination and the acetylcholinesterase (AchE) qualitative test have been performed on amniotic fluid samples from 33 normal pregnancies, 44 pregnancies with fetal malformations and 8 normal pregnancies with elevated amniotic fluid alphafetoprotein (3 false positive AFP results, 5 contaminations with fetal blood). The validities of these three tests in detecting abnormal pregnancies are compared. The usefulness of the existing complementary tests in the detection of neural tube defects in a low neural tube defect incidence area is discussed. Risk figures for open spina bifida according to the prior risk situation and the results of maternal serum AFP, amniotic fluid AFP, AchE qualitative test and ultrasound examination have been calculated.