No abstract

A 30-year-old nulliparous woman was seen for a detailed ultrasound scan at 20 weeks of gestation. The scan revealed a male fetus with truncus arteriosus, membranous ventricular septal defect, absent thymus and sacral meningomyelocele. A 46,XY karyotype with a 22q11 deletion was detected. The parents chose to terminate the pregnancy. The pathological autopsy showed normal facial structures, minimal ventricular dilatation in the brain and a sacral meningomyelocele. Overlapping toes and a left claw-hand were also noted. An aplastic thymus with absent parathyroid glands was detected. The cardiac examination was consistent with the ultrasound diagnosis. The parental karyotypes were both normal. Kousseff syndrome is caused by a chromosome 22q11 deletion. It includes sacral meningomyelocele and conotruncal heart defects, unlike DiGeorge syndrome. Obstetricians should consider this a not so rare entity when they detect conotruncal abnormalities and a meningomyelocele as part of a 22q11.2 deletion syndrome.

SUMMARYWilliams-Beuren syndrome is a rare and usually sporadic genetic anomaly with an estimated frequency of 1:25,000, that also has cardiac defects due to the effect on the elastin locus of a deletion on the 7 th chromosome. Identical twin boys presented with exercise-induced syncope. Echocardiographic examination revealed severe calcification at the aortic valves, mitral anterior leaflets, and mitral annuli in both cases. A basal interventricular septum was also involved in one case. Doppler evaluation demonstrated severe aortic stenosis with a peak gradient of 112 and 118 mmHg in both cases. Moderate mitral stenosis was also detected in one twin. We performed aortic mechanical valve replacement and dilated the aortic annulus with Nick's procedure and evaluated the diagnosis and therapy methods in light of the literature. As a result, we determined that these boys are the first monozygotic twins who were diagnosed during childhood. (Jpn Heart J 2004; 45: 877-883)

Down's syndrome (DS) has the highest incidence among chromosomal disorders and is a predisposing factor in acute leukemia pathogenesis. DS patients are sensitive to both physical and chemical inducers at the DNA level. Studies on beta-carotene, an antioxidant, suggested the there is a relationship between high beta-carotene diet and reduced tumor incidence in humans indicating that beta-carotene is a chemopreventive agent against cancer. Sister chromatid exchange (SCE) is known as a sensitive parameter among the genotoxicity tests. In this study, we aimed to investigate the in vitro effect of beta-carotene on SCE frequencies in 7 DS patients and 7 healthy controls aged between 0-16 years. A direct leukomogenic agent Mitomycin-C (MMC) was used as a powerful SCE inducer. Addition of MMC to the cultures alone resulted in a significant enhancement of SCE frequencies in both groups when compared to the spontaneous values. In the study, beta-carotene seemed to decrease MMC induced mean SCE/cell values, but did not have an effect on unstimulated cells. As this is a limited study, it is hard to conclude that beta-carotene is a chemopreventive agent in DS patients, although our results seem to support other investigators' reports.

We present prenatal diagnosis of a de novo translocation (5;11) in a hydropic fetus with ultrason abnormalities. In our case, karyotype analysis of the fetus, mother and father provided evidence of a de novo translocation, that might explain the NIHF.