Potential errors with rapid analysis techniques: partial duplication 21q resulting from a paternal paracentric insertion uncovered in chorionic villus sampling by fluorescence in situ hybridization.

We report on partial duplication 21q resulting from a paternal insertion identified during prenatal diagnosis. While performing interphase fluorescence in situ hybridization (I-FISH), we were able to identify 3 signals of the LSI 21 Spectrum Orange probe with chorionic villus sampling. Using standard cytogenetic analysis, I-FISH and GTG banding, structural aberrations in 21q in the parents and in the fetus could not be reliably determined. Applying metaphase fluorescence in situ hybridization (M-FISH), we identified a recombinant chromosome 21 carrying an interstitial duplication of the Down syndrome critical region inherited from the father. Both data from our analysis and published literature recommend the use of rapid testing methods such as I-FISH and standard cytogenetic analysis in prenatal diagnosis. It became obvious that I-FISH would not detect such a particular aberration. Thus, karyotyping, I-FISH and M-FISH should be performed in all Down syndrome cases.

[Muscular hypotonia, developmental retardation, speech delay and mildly dysmorphic features: 22q13 deletion syndrome (Phelan-McDermid Syndrome) as an important differential diagnosis]. / Muskuläre Hypotonie, Entwicklungsretardierung, Sprachentwicklungsstörung und geringgradige Dysmorphiezeichen: 22q13-Deletions-Syndrom (Phelan-McDermid-Syndrom) als wichtige Differenzialdiagnose.

BACKGROUND: Clarifying the cause of global developmental and speech delay is of considerable significance in pediatrics. We present the clinical phenotype of the 22q13 deletion syndrome - also known as Phelan-McDermid syndrome - and show the diagnostic options. PATIENT: We report on a female patient with muscular hypotonia, tall stature, minor facial dysmorphism, retarded motor and mental development, and severe speech delay. METHOD: Chromosomal analysis was performed first on peripheral lymphocytes on GTG-banded chromosomes. Fluorescence in situ hybridization (FISH) analysis was carried out using the dual-color LSI DiGeorge/VCFS Region Probe (TUPLE1, N25) (Vysis/Abbott) and the subtelomeric probe tel 22q13.3 (Tel Vysion 22q). RESULTS: The analysis of metaphase chromosomes at 450 band resolution showed a normal female karyotype 46,XX. FISH analysis revealed a 22q13 deletion. CONCLUSION: Muscular hypotonia and developmental delay are non-specific findings observed in many genetic syndromes. In association with severe speech delay and normal or advanced growth pediatricians should consider 22q13 deletion syndrome as a potential cause and initiate a genetic examination.

Evidence for a founder effect of the germline fumarate hydratase gene mutation R58P causing hereditary leiomyomatosis and renal cell cancer (HLRCC).

We report on the results of clinical investigation, pedigree analysis, mutation screening and haplotyping in a family with the syndrome of multiple cutaneous and uterine leiomyomas (MCUL1) and a germline missense mutation (R58P) in the fumarate hydratase gene (FH). We provide evidence for a founder effect for the identified mutation and distant relationship of our family to another familial case of MCUL1 associated with renal cell cancer, which was recently published with the same mutation.

[Neurofibromatosis type 1 and associated clinical abnormalities in 27 children]. / Neurofibromatose Typ 1 und assoziierte Krankheiten bei 27 Kindern und Jugendlichen.

Neurofibromatosis type 1 is the most common of the phakomatoses and the clinical follow-up is an interdisciplinary challenge. The data of 27 patients with NF1 were systematically reviewed and compared to data from the literature. All of our patients had clinical signs of NF1. Besides the classic criteria café-au-lait spots (100%), freckling (48,1%), positive family history (44,1%), neurofibromas (40,7%), Lisch nodules (22,2%) and optic pathway tumors (22,2%) there were developmental delay (40,7%), macrocephaly (33,3%), strabism (29,6%), scoliosis (18,5%), epilepsy (14,8%), pubertal anomalies (14,8%), short stature (11,1%) and tics. Morphologically, CNS hamartomas (55,5%), astrocytomas (22,2%) and one pheochromocytoma became apparent. Special findings consist of one aneurysm of internal carotic arteria, juvenile xanthogranulomas, a case of pulmonary stenosis and an intracardial tumor. Four new mutations in the NF1 gene were found. Regular screening of optic glioma with MRI had no clinical significance. In contrast to other authors, one of our patients with optic glioma showed clinical progress after twelve years of age. The detection of astrocytomas led only to therapeutic consequences, when clinical signs or symptoms occurred. As with other authors, we found no potential for CNS hamartoma to proliferate. In three cases with pubertal anomalies we found CNS gliomas, which indicates the need for MRI. The expense of screening, apart from clinical surveillance, seems inadequate in relation to clinical relevance and costs. We describe four new mutations in the NF1 gene; there have been no specific genotype-phenotype correlations. Neurofibromatosis type 1 and associated clinical abnormalities in 27 children.

Clinical significance and neuropathology of primary MADD in C34-T and G468-T mutations of the AMPD1 gene.

OBJECTIVE: Primary myoadenylate deaminase deficiency (MADD) is probably the most frequent inborn metabolic myopathy with a prevalence of up to 2%. It is the result of mutations in the AMPDI gene, the most common of which is a C34-T transition in exon 2. The importance of the more rare mutation G468-T in exon 5 is uncertain. Primary objective was to elucidate the clinical significance of the enzyme disorder, which remains unclear since its first description in 1978. We further examined the existence of an association of MADD with other muscle disorders, such as malignant hyperthermia and rhabdomyolysis, as was suspected in earlier studies. MATERIAL AND METHODS: In a large collection of 1673 muscle biopsies that had been stored deep frozen we identified 33 cases of primary MADD, 12 of which without any other coinciding muscle diseases, by histochemical, biochemical and molecular genetic examinations. Clinical and laboratory data was collected. By additional examination of randomly chosen blood samples we identified one person carrying the rare compound heterozygosity C34-T/ G468-T, who was examined in clinical respects and a muscle biopsy was taken. RESULTS: As underlying mutation, the most common transition C34-T/C 143-T was detected in 33 cases. One patient carried the compound heterozygosity C34-T/G468-T. The overall frequency of MADD in the contingent was 1.8%. Only three patients out of 12 with isolated primary MADD suffered from muscle complaints, one of whom did not experience the typical symptoms of exercise related myalgia, muscle cramps and weakness as described by Fishbein. The patient carrying C34-T/G468-T was a fully healthy female. She had never experienced any muscle complaints. Any association with other neuromuscular disorders, if not completely ruled out, was found to be very unlikely. CONCLUSION: The results suggest that MADD itself is unlikely to be solely responsible for the manifestation of muscular symptoms. It is probable that either the loss of a compensation mechanism or coexistent disturbances in muscle metabolism which are unidentified so far are required for the emergence of complaints.

Histologic analysis of gonadal tissue in patients with Ullrich-Turner syndrome and derivative Y chromosomes.

To identify patients who had Ullrich-Turner syndrome (UTS) and were at risk for gonadoblastoma or associated germ cell tumors, molecular genetic analysis was carried out to detect Y chromosomal sequences. From peripheral blood samples of 5 patients who had cytogenetically confirmed UTS, genomic DNA was extracted and screened for Y chromosomal sequences by polymerase chain reaction. The morphology of the gonadal tissues was compared with results from polymerase chain reaction. Three phenotypic females showed UTS mosaicism with normal X chromosome accompanied by Y chromosomal material, and 2 patients showed marker chromosomes. Molecular analysis represented loci PABY, SRY, ZFY, TSPY, DYZ3, DYZ1 DXYS, 19Y, DYS-273, DYS-148, DYS218, DYS224, and DYZ1. Three patients showed gonadal tumors (1 with unilateral gonadoblastoma, 1 with unilateral dysgerminoma, and 1 patient had both tumors in 1 gonad). Molecular genetic screening for Y chromosomal sequences may be useful as an additional tool for the identification of patients at risk for a gonadal tumor. Careful, complete processing, including step sectioning, of the gonadectomy specimens to detect small lesions is recommended.

[Hereditary multiple exostoses. Molecular genetic analysis of the EXT1 gene in an unusual family]. / Hereditäre multiple Exostosen. Molekulargenetische Analyse des EXT1-Gens in einer ungewöhnlichen Familie.

Hereditary multiple exostosis (HME), a disorder inherited in an autosomal dominant manner, is characterized by multiple projections of bone, mainly at the extremities. The risk of malignant transformation of the exostoses is estimated to be up to 2%. The most common underlying cause of the disease involves mutations in either the EXT1 or the EXT2 gene. We report on the clinical and molecular findings in a family affected with HME.A mother and her three children from different partnerships, all clinically diagnosed with HME, were referred for genetic counseling. Subsequently, molecular analysis of the EXT1 gene was performed according to standard procedures. We identified a mutation in the EXT1 gene in all four affected family members (delA in codon 133). This mutation has not been previously described and is suggested to cause the disease in this family. Identification of disease causing mutations in patients with HME and their relatives can help to improve the clinical management of tumor prevention, early tumor detection, and orthopedic therapy.

Another case of autosomal dominant exstrophy of the bladder.

OBJECTIVE: Exstrophy of the bladder is a rare malformation due to an anterior midline defect. Most cases of this condition with variable expression occur sporadically, but there are some cases indicative of a strong genetic component apart from environmental factors. This is a report about another rare mother-child pair with bladder exstrophy. METHODS: We present the clinical data of a familial case of bladder exstrophy with an affected mother and her equally affected male fetus. RESULTS: Prenatal diagnosis of bladder exstrophy in the fetus was assessed by ultrasound at the 19th gestational week and was confirmed after termination of pregnancy at the 21st gestational week. CONCLUSION: The present case may be additional evidence for an autosomal dominant inherited variant of this malformation complex with implication for counselling of affected patients.

[Molecular genetic mutation analysis of the PTPN11 gene in the multiple lentigines (LEOPARD) syndrome]. / Molekulargenetischer Mutationsnachweis im PTPN11-Gen beim Multiple-Lentigines- (LEOPARD-)Syndrom.

BACKGROUND AND OBJECTIVE: LEOPARD syndrome (MIM #151100) is a rare autosomal dominant condition with characteristic skin anomalies, facial dysmorphism, hypertelorism, cardiac anomalies, and occasional conductive hearing loss. Mutations in the PTPN11 gene are described as the causal gene defect for the clinical features of Noonan syndrome (MIM #163950), but also for LEOPARD syndrome. For confirmation of the clinical diagnosis of multiple lentigines syndrome, the molecular genetic mutation analysis in the PTPN11 gene could be helpful. PATIENTS/METHODS: We report on a family with LEOPARD syndrome in which the mutation analysis in the father and his daughter in the PTPN11 gene was carried out us:ng PCR, DHPLC, and automated sequencing. RESULTS: We could identify both father and daughter as carriers of the mutation Y279C in the PTPN11 gene, which is known as a disease-related mutation. CONCLUSIONS: The allelic affinity to Noonan syndrome could thus be further supported.

Partial trisomy 22 resulting from rearrangements between chromosomes 11/22 and 16/22: a report of two cases.

UNLABELLED: Two male infants with partial trisomy 22 resulting from a rearrangement between chromosomes 11/22 and 16/22 were admitted to the Children's Hospital of the University of Leipzig within the space of two months. The characteristic phenotype of the infants is described and compared with the data on liveborn infants with trisomy 22, as reported in the literature. One of the infants reported here showed a prenatally detected hygroma colli. To the best of our knowledge this is the first description of a hygroma colli in this chromosomal disorder. CONCLUSION: Infants with trisomy 22 can present with variable phenotypes. It is important to bear the phenotype of chromosome 22 infants in mind.

Characterization of chromosomal aberrations in a case of glioblastoma multiforme combining cytogenetic and molecular cytogenetic techniques.

A case of glioblastoma multiforme (GBM) that was investigated with a broad spectrum of cytogenetic and molecular cytogenetic techniques is reported. The results of cytogenetic studies, interphase fluorescence in situ hybridization, comparative genomic hybridization, and spectral karyotyping (SKY) are reported. Various structural chromosomal aberrations were identified, among which aberrations involving chromosome arm 2p were especially frequent. Using SKY, six translocations not previously described in GBM are reported.

[Current aspects of the diagnosis of malignant hyperthermia]. / Aktuelle Aspekte der Diagnostik der malignen Hyperthermie.

OBJECTIVES: The aim of this work was to give a survey of experiences and results obtained over a period of 15 years of diagnosis of malignant hyperthermia in the MH centre in Leipzig. The new branch of MH diagnosis, the molecular genetics and its general diagnostic potential will be presented in more detail. METHODS: The in vitro contracture test (IVCT), which has been used in our department since 1986, represents the standard method for determining disposition to MH and in addition, suspected MH events were analysed by the clinical grading scale (CGS). In 1999, the diagnosis of MH in our centre was supplemented by molecular genetic examination of the skeletal ryanodine receptor gene (RYR1). RESULTS: A total of 1,456 muscle tests (IVCT) in patients with a potential MH disposition, provided 376 MH susceptible (MHS), 121 MH equivocal (MHE) and 921 MH negative (MHN) results. Out of these 309 persons had a previous clinical MH event, but for the majority of these persons a real MH disposition could be excluded by the IVCT (197 MHN). In 99 independent MH families, the RYR1 was genetically screened identifying a mutation in 46, whereby 18 different RYR1 point mutations were found of which 4 (Arg401Cys, Ile2182Phe, Gly2375Ala, Ile2453Thr) have not yet been published. CONCLUSIONS: The disposition to MH may be assessed by the IVCT, DNA analysis and with limitations by the clinical phenotype. The IVCT represents a highly specific method, the DNA analysis appears to be very specific. Under defined conditions an alternative use of the methods is possible. However, these methods should not be regarded as in competition but rather their potential should be complementary or used in specific situations in order to avoid non-detection of MH events in affected families.