Prenatal detection of a giant bilateral thoracic vascular lesion: prognostic evaluation and genetic aspects.

We describe a giant bilateral vascular mass in the skin of the chest diagnosed by ultrasound investigation in a fetus of 20 gestational weeks. Ultrasound and colour Doppler investigations detected no signs of early congestive heart failure but rapid and excessive enlargement of the vascular mass. Indications of increased fetal blood volume were found. The fetus had additional minor anomalies. Early in utero manifestation suggests a severe vascular malformation.     

Technical aspects of neonatal screening using tandem mass spectrometry. Report from the 4th meeting of the International Society for Neonatal Screening

Quantitative analysis of amino acids (AA) and acylcarnitines using tandem mass spectrometry is an emerging technology used to screen neonatal dried blood spot samples for disorders in the metabolism of AA, organic acids and fatty acids. This paper provides a brief review of some of the technically oriented issues which emerged at the 4th meeting of the International Society for Neonatal Screening in Stockholm, 1999. The information covers sample preparation, instrumentation, data acquistion modes, internal standards, interpretation, confounding factors and practical screening experience.     

Surgical outcome after phototherapeutic keratectomy in patients with TGFBI-linked corneal dystrophies in relation to molecular genetic findings

Purpose  To evaluate the correlation between surgical outcome after phototherapeutic keratectomy in patients with autosomal dominant transforming growth factor, beta-induced (TGFBI)-linked corneal dystrophies (CD) and molecular genetic findings regarding the TGFBI gene. Methods  Twelve patients were examined to investigate genotype by direct sequencing of the TGFBI gene. Twenty eyes of 12 patients were treated with phototherapeutic keratektomy (PTK) to remove superficial corneal opacifications and to decrease recurrent erosions. Surgical outcome, including visual improvement, recurrence of opacifications, postoperative complications, and additional therapeutic proceedings were reported and compared with the molecular genetic results. Results  Four different missense mutations were identified within the coding region of the TGFBI gene: Arg124Cys in one eye, Arg555Trp in nine eyes, Arg124His in four eyes and Gly623Arg in six eyes. In all eyes the PTK was successful without clinically significant recurrent opacifications after a mean follow-up time of 17.6 months (min 3 months, max 42 months). The best corrected visual acuity (BCVA) improved with an average increase of 3.1 lines (minimum 2 lines, maximum 5 lines). In one eye (Arg124Cys), we observed delayed wound healing and a delayed increase in BCVA, in two eyes we performed an Epilasik to correct remaining hyperopia, and in four eyes we fitted rigid gas-permeable tricurve contact lenses to correct the remaining irregular astigmatism. Conclusions  The variable genotypes in patients with TGFBI-linked corneal dystrophies lead to significantly different results after surgical treatment. The Gly623Arg mutation seems to be an optimum genotype on which to perform PTK even in older patients. It is essential to determine the genotype in order to standardize the PTK treatment and to evaluate the success in TGFBI-linked corneal dystrophies.     

A missense mutation in the ZFHX1B gene associated with an atypical Mowat-Wilson syndrome phenotype

Mowat-Wilson syndrome (MWS) is a rare mental retardation-multiple congenital anomalies syndrome associated with typical facial dysmorphism. Patients can show a variety of other anomalies like short stature, microcephaly, Hirschsprung disease, malformations of the brain, seizures, congenital heart defects and urogenital anomalies. Mutations leading to haploinsufficiency of the ZFHX1B gene have been described as the underlying cause of this condition. We report on the clinical findings in a 2(1/2)-year-old boy with some aspects out of the MWS-spectrum in addition to unusual anomalies and a novel missense mutation in the ZFHX1B gene.     

Diaphragmatic defects,limb deficiencies,and ossification defects of the skull: A distinctive malformation syndrome

We report on prenatal and postnatal findings in 4 consecutive fetuses with a pattern of severe congenital anomalies who were born to a healthy nonconsanguineous couple. The spectrum of malformations includes diaphragmatic defects, hypoplastic lungs, omphalocele, limb deficiencies, syndactyly of toes, and ossification defects of the skull. This specific spectrum of anomalies is not fully compatible with that of any established syndrome. No prenatal exposure to any possible teratogen was found. Family history is suggestive for autosomal recessive inheritance, even though germ-line mosaicism in one of the parents cannot completely be excluded. © 1996 Wiley-Liss, Inc.     

Expanding the spectrum of TBX5 mutations in Holt-Oram syndrome: detection of two intragenic deletions by quantitative real time PCR, and report of eight novel point mutations

Mutations in the gene TBX5 cause Holt-Oram syndrome (HOS), an autosomal dominant disorder characterized by anterior (i.e., radial ray) upper limb malformations and congenital heart defects and/or cardiac conduction anomalies. The detection rate for TBX5 mutations in HOS patients has been given as 30-35% in most reports. However, a detection rate of 74% was reported when strict clinical inclusion criteria for HOS were applied prior to TBX5 analysis. Still, in a significant proportion of typical HOS cases no mutation can be found within the TBX5 coding region and flanking intronic sequences. One explanation could be that large but submicroscopic deletions of TBX5 could cause HOS, yet only one such TBX5 deletion has been reported to date. We developed a quantitative Real Time PCR strategy to detect large, submicroscopic deletions in TBX5. Using this assay, we screened a total of 102 TBX5 mutation negative patients and discovered two novel intragenic deletions. One deletion of 7756 bp removes exon 6 and a considerable part of the neighboring intronic sequences, and the other of 3695 bp removes exon 9 with the stop codon and the 3'UTR completely as well as a part of the preceding intron 8. We conclude that quantitative Real Time PCR is a reliable method to detect submicroscopic deletions within TBX5. However, such deletions explain only approximately 2% of the TBX5 mutational spectrum in HOS cases. In addition, we also present eight novel TBX5 mutations (three nonsense, one splice mutation, four short deletions) as detected by direct sequencing in 21 families not previously analyzed for mutations.     

35-jähriger Patient mit ausgeprägter Thromboembolie

We report a case of a 35 year old male with severe deep vein thrombosis of the lower limb on both sides and pulmonary embolism. A Klinefelter's mosaic (47,XXY [81%]/48,XXXY [19%]) was diagnosed. Because no other cause for this thromboembolism was found, we assume that in part, it was caused by the Klinefelter's mosaic. In all male patients presenting with thromboembolism, especially those with an unusual habitus, a Klinefelter's syndrome should be considered as differential diagnosis. Testosterone substitution therapy should be started in all patients with Klinefelter's syndrome to prevent further disease.     

Molecular genetic and ocular findings in patients with holt-oram syndrome

PURPOSE: The autosomal dominant Holt-Oram syndrome (HOS) is characterized by upper limb and cardiac septal defects. Mutations of the TBX5 gene have been identified as the underlying gene defect in HOS. Embryonic expression of TBX5 has been found in the human retina. This is the first report of ocular findings in two unrelated families with mutations in the TBX5 gene. METHODS: Six living persons affected with HOS and 10 unaffected family members were subjected to mutation analysis and complete ophthalmological examination, including electrophysiological examinations (EOG and flash ERG). RESULTS: A heterozygous single base-pain substitution in exon 5 (408C --> A) was detected in all affected patients. All examined affected patents were ophthalmological asymptomatic with normal EOG. A scotopic elongated b-wave latency was found in affected family members who were older than 35 years. The ERG was normal in the young patients. CONCLUSIONS: Haploinsufficiency of TBX5 alters the dorsal-ventral polarity in developing eye vesicles without amy detected functional loss in human. Slight ERG abnormalities later in life may be a result of changes induced by the inner ganglion cell layer in the inner nuclear layer.     

Die moderne Genetik — Eine Einführung

Zusammenfassung Die Fortschritte der modernen Genetik sind nicht ohne Probleme. W?hrend es früher so war, da? die Verantwortung für eine Untersuchung vor allem beim Arzt lag, ist es heute so, da? die moderne Genetik zunehmend auch dem Patienten Verantwortung übertr?gt. Gerade in der Versorgung schwangerer Frauen wird ein Widerspruch und Dilemma deutlich, das schwierig zu überbrücken ist: 99% aller Schwangeren m?chten eine v?llig normale Schwangerschaft und Geburt, bis zu dem Zeitpunkt, wenn ein Problem auftritt: denn dann m?chte jede Patientin den h?chstm?glichen technischen Standard. Das Wissen und die technischen Voraussetzungen müssen daher zur Verfügung stehen, die Anwendung kann sich jedoch nur am Einzelfall orientieren.