Search

Background Klinefelter syndrome (KS), a common sex chromosome aneuploidy (47,XXY) is diagnosed prenatally with an incidence of 0.15%. The diagnosis is generally incidental, since there are no typical malformations on ultrasound (US). Once detected, genetic counseling is often difficult and the parents' decision to continue or terminate the pregnancy is greatly dependent on the amount and nature of the information provided. We sought to assess the pregnancy outcomes (i.e. continuation versus termination) and the influence of multidisciplinary centers for prenatal diagnosis on parental decisions in cases of KS. Methods From 1985 to 2009, 188 prenatal diagnoses of KS were made by 11 participating laboratories in mainland France. In each case, the karyotype indication, parental ages, year of prenatal testing, sampling procedure, karyotype, associated US findings and outcome were recorded. Results and conclusions The pregnancy termination rate declined markedly over time, from 46.9% before 1997 to 11.6% thereafter, in line with the introduction of new legislation on prenatal diagnosis for medical reasons and, more specifically, the creation of multidisciplinary prenatal diagnosis centers. However, an additional microdeletion in one KS infant who exhibited echogenic bowel on US was unfortunately diagnosed postnatally. This raises the question as to whether array comparative genomic hybridization should be prenatally advised when US abnormalities are detected, in line with advice for fetuses with a normal karyotype.

A locus on distal 9p has been reported to be deleted in patients with mental retardation, craniofacial dysmorphic traits, notably trigonocephaly, and a high frequency of genital and/or gonadal anomalies (Alfi's syndrome).1 More recently, some cases of 46,XY male to female sex reversal without dysmorphic traits have been described in association with distal deletions of 9p.2–5 46,XY patients described so far have had gonadal anomalies ranging from streak gonads, to partially masculinised dysgenetic gonads, to normal testes. A family of genes containing a unique zinc finger DNA binding domain, which has been called DM, as it is contained in two proteins involved in invertebrate sex determination, doublesex and mab-3, has recently been recognised. Three genes belonging to this family have been identified on 9p24.3, immediately proximal to the centromeric boundary of the minimal region, which is required in two copies for testis development.5 The first gene identified was termed DMRT1 and the two additional DM gene family members are placed in tandem more distally to the breakpoint of the minimal deleted region.6,7 DMRT1 is transcribed only in the embryonic gonads of both sexes and in fetal and adult testis, and is required for postnatal differentiation of both somatic and germ cells in the mouse testis.8 Therefore, this gene is a good candidate to explain the 46,XY sex reversal associated with 9p deletions. Recently, a 1 year old 46,XX female patient with premature ovarian failure and deletion of 9p was reported.9 This led to the suggestion of a role for a gene located on 9p in both male and female gonadal development. DMRT1 represents a good candidate for a function in both sexes as it is expressed in the genital ridge in both sexes in mouse and humans.7,8 Here, we report …

Fourteen lysosomal enzymes were compared in 20 cultured cell lines from chorionic biopsy and corresponding embryonic tissue after voluntary abortions. Enzymatic expression appears to be similar in cultured cells from both sources with some slightly higher levels for chorionic villi. We stress the importance of culturing chorionic villi especially in the case of enzymes (alpha-L-iduronidase) or diseases (I cell disease) whose expression is unusual in fresh trophoblast tissue.