[Fanconi Anemia, Complementation Group D1 Caused by Biallelic Mutations of BRCA2 Gene--Case Report]. / Fanconiho anémie, komplementacní skupina D1 v dusledku bialelické mutace genu BRCA2--kazuistika.

Fanconi anemia is a rare autosomal recessive disorder, clinically and genetically heterogeneous, characterized by typical clinical features, such as short stature, microcephaly, skeletal abnormalities, abnormal skin pigmentations, developmental delay and congenital heart, kidney anomalies etc. Pancytopenia leading to bone marrow failure occurs in the first decade. Patients with Fanconi anemia have a high risk of hematologic malignancies and solid tumors. The diagnosis of Fanconi anemia is based on cytogenetic testing for increased rates of spontaneous chromosomal breakage and increased sensitivity to diepoxybutane or mitomycin C. Fanconi anemia is a heterogeneous disorder, at least 15 complementation groups are described, and 15 genes in which mutations are responsible for all of the 15 Fanconi anemia complementation groups have been identified. Unlike other Fanconi anemia complementation groups, for complementation group D1 (FANCD1), the bone marrow failure is not a typical feature, but early-onset leukemia and specific solid tumors, most often medulloblastoma and Wilms tumor, are typical for this complementation group.

45,X/46,X,psu dic(Y) gonadal dysgenesis: influence of the two cell lines on the clinical phenotype, including gonadal histology.

A child born with ambiguous genitalia (Prader III) was found to have a 45,X[92.2%]/46,X,psu dic(Y)(p12)[7.8%] karyotype in peripheral blood lymphocytes. The testosterone level was consistent with that of a normal male; however, gonadotropins were elevated. Ultrasound and endoscopy of the urogenital sinus revealed well-developed Müllerian structures. At 3.5 months, the child was operated for right-sided incarcerated hernia, and the gonad situated at the inguinal region was biopsied and classified as primitive testis. Based on the presence of Müllerian structures, anatomy of external genitalia and wish of the parents, the child was assigned female gender. She underwent removal of the left gonad at 4 months during another acute surgery; histology was similar to the right gonad. The rest of the right gonad was removed at 16 months, and feminizing genitoplasty took place at 3 years. The right and left gonad contained 28 and 22% of cells with a Y chromosome, respectively. During further histological examination, dysgenetic features of the gonads were discovered. Some germ cells displayed abnormal development based on the specific expression of immunohistochemical markers (OCT3/4, TSPY, KITLG), indicating a possible risk for future malignant germ cell tumor development. Contribution of the 45,X cell line to the phenotype was also observed: the patient developed celiac disease, and her growth pattern resembled that of Turner syndrome responding to growth hormone treatment.

Prepubertal girls with Turner syndrome and children with isolated SHOX deficiency have similar bone geometry at the radius.

CONTEXT: The low bone mineral density (BMD) and alterations in bone geometry observed in patients with Turner syndrome (TS) are likely caused by hypergonadotropic hypogonadism and/or by haploinsufficiency of the SHOX gene. OBJECTIVE: Our objective was to compare BMD, bone geometry, and strength at the radius between prepubertal girls with TS and children with isolated SHOX deficiency (SHOX-D) to test the hypothesis that the TS radial bone phenotype may be caused by SHOX-D. DESIGN AND SETTING: This comparative cross-sectional study was performed between March 2008 and May 2011 in 5 large centers for pediatric endocrinology. PATIENTS: Twenty-two girls with TS (mean age 10.3 years) and 10 children with SHOX-D (mean age 10.3 years) were assessed using peripheral quantitative computed tomography of the forearm. MAIN OUTCOMES: BMD, bone geometry, and strength at 4% and 65% sites of the radius were evaluated. RESULTS: Trabecular BMD was normal in TS (mean Z-score = -0.2 ± 1.1, P = .5) as well as SHOX-D patients (mean Z-score = 0.5 ± 1.5, P = .3). At the proximal radius, we observed increased total bone area (Z-scores = 0.9 ± 1.5, P = .013, and 1.5 ± 1.4, P = .001, for TS and SHOX-D patients, respectively) and thin cortex (Z-scores = -0.7 ± 1.2, P = 0.013, and -2.0 ± 1.2, P < .001, respectively) in both groups. Bone strength index was normal in TS as well as SHOX-D patients (Z-scores = 0.3 ± 1.0, P = .2, and 0.1 ± 1.3, P = .8, respectively). CONCLUSIONS: The similar bone geometry changes of the radius in TS and SHOX-D patients support the hypothesis that loss of 1 copy of SHOX is responsible for the radial bone phenotype associated with TS.

Bone geometry and volumetric bone density at the radius in patients with isolated SHOX deficiency.

UNLABELLED: The short stature homeobox-containing gene (SHOX) plays an important role in bone development and growth. We aimed to assess bone geometry and volumetric bone mineral density at the radius in patients with isolated SHOX deficiency and to relate these bone parameters to the severity of disproportion between the upper and the lower body segment. 17 patients with isolated SHOX deficiency (median age 12.3 yrs, range 6.7-37.2, 12 children and 5 adults) were examined by peripheral quantitative CT (pQCT) at the non-dominant forearm. Results were expressed as Z-scores using published reference data. Linear regression analyses were performed to describe associations between pQCT parameters and the severity of disproportion expressed as sitting height to standing subischial leg height ratio. Trabecular volumetric bone mineral density (vBMD) at the distal radius was normal, whereas cortical vBMD was decreased (mean Z-scores 0.34±1.5, n.s., and -2.2±2.2, p<0.001, respectively). Total bone cross-sectional area was enlarged at the diaphysis (2.1±1.2, p<0.001), while cortical bone cross-sectional area was normal (-0.51±1.4, n.s.). Consequently, cortical thickness was decreased (-1.2±1.3, p<0.01). The polar strength-strain index as a surrogate of long bone strength was normal (0.40±1.4, n.s.). We found no associations between pQCT parameters and the severity of disproportion. CONCLUSIONS: Patients with isolated SHOX deficiency are characterized by decreased cortical vBMD and cortical thickness and enlarged diaphysis. As similar changes have been described in girls with Turner syndrome, these findings suggest that haploinsufficiency of SHOX could cause characteristic skeletal anomalies at the radius.

Mechanism and genotype-phenotype correlation of two proximal 6q deletions characterized using mBAND, FISH, array CGH, and DNA sequencing.

Proximal 6q deletions have a milder phenotype than middle and distal 6q deletions. We describe 2 patients with non-overlapping deletions of about 15 and 19 Mb, respectively, which subdivide the proximal 6q region into 2 parts. The aberrations were identified using karyotyping and analysed using mBAND and array CGH. The unaffected mother of the first patient carried a mosaic karyotype with the deletion in all metaphases analysed and a small supernumerary marker formed by the deleted material in about 77% of cells. Her chromosome 6 centromeric signal was split between the deleted chromosome and the marker, suggesting that this deletion arose through the centromere fission mechanism. In this family the location of the proximal breakpoint in the centromere prevented cloning of the deletion junction, but the junction of the more distal deletion in the second patient was cloned and sequenced. This analysis showed that the latter aberration was most likely caused by non-homologous end joining. The second patient also had a remarkably more severe phenotype which could indicate a partial overlap of his deletion with the middle 6q interval. The phenotypes of both patients could be partly correlated with the gene content of their deletions and with phenotypes of other published patients.

[Pendred syndrome among patients with hypothyroidism: genetic diagnosis, phenotypic variability and occurrence of phenocopies]. / Pendreduv syndrom u pacientu s hypotyreózou: genetická diagnostika, fenotypová variabilita a výskyt fenokopií.

BACKGROUND: Pendred syndrome (OMIM274600) is one of the causes of congenital hypothyroidism due to thyroid dyshormonogenesis. It is an autosomal recessive disease classically characterized by dyshormonogenetic goitre and sensorineural deafness. It is caused by mutations in PDS/SLC26A4 gene encoding for pendrin--an anion transporter, mostly expressed in the thyroid gland and the inner ear. The thyroid impairment in Pendred syndrome develops only in 80% of affected individuals in form of a euthyroid or hypothyroid goitre, which is rarely present at birth, when it can be diagnosed by the neonatal screening for congenital hypothyroidism. The study was aimed to identify patients with Pendred syndrome among children with congenital or postnatal non-autoimmune hypothyroidism and subsequently confirm the diagnosis by finding mutations in the PDS/SLC26A4 gene. METHODS AND RESULTS: We examined two-hundred thirty-six Caucasians with hypothyroidism diagnosed by screening or developing later in childhood. The clinical diagnosis of Pendred syndrome was based on the laboratory and ultrasonographic signs of thyroid dyshormonogenesis (elevated TSH, low T4/fT4, goitre or normal thyroid volume) in association with sensorineural hearing loss. In subjects clinically diagnosed as Pendred syndrome, we sequenced all 21 exons of the PDS/SLC26A4 gene and their flanking intron-exon junctions. Among 236 children, nine fulfilled the diagnostic criteria of Pendred syndrome. In four, the diagnosis was confirmed by identification of mutations in the PDS/SLC26A4 gene, the remaining five patients were concluded phenocopies. CONCLUSIONS: Our study confirms the high phenotypic variability of thyroid impairment in Pendred syndrome and underlines the necessity of a molecular-genetic investigation for establishing the diagnosis in regard of the great number of phenocopies. However, from the endocrinologist's point of view, the genetic testing is only reasonable in patients with congenital hypothyroidism due to dyshormonogenesis in association with sever to profound sensorineural hearing loss.

Two independent chromosomal rearrangements, a very small (550 kb) duplication of the 7q subtelomeric region and an atypical 17q11.2 (NF1) microdeletion, in a girl with neurofibromatosis.

Most patients with neurofibromatosis (NF1) are endowed with heterozygous mutations in the NF1 gene. Approximately 5% show an interstitial deletion of chromosome 17q11.2 (including NF1) and in most cases also a more severe phenotype. Here we report on a 7-year-old girl with classical NF1 signs, and in addition mild overgrowth (97th percentile), relatively low OFC (10th-25th percentile), facial dysmorphy, hoarse voice, and developmental delay. FISH analysis revealed a 17q11.2 microdeletion as well as an unbalanced 7p;13q translocation leading to trisomy of the 7q36.3 subtelomeric region. The patient's mother and grandmother who were phenotypically normal carried the same unbalanced translocation. The 17q11.2 microdeletion had arisen de novo. Array comparative genomic hybridization (CGH) demonstrated gain of a 550-kb segment from 7qter and loss of 2.5 Mb from 17q11.2 (an atypical NF1 microdeletion). We conclude that the patient's phenotype is caused by the atypical NF1 deletion, whereas 7q36.3 trisomy represents a subtelomeric copy number variation without phenotypic consequences. To our knowledge this is the first report that a duplication of the subtelomeric region of chromosome 7q containing functional genes (FAM62B, WDR60, and VIPR2) can be tolerated without phenotypic consequences. The 17q11.2 microdeletion (containing nine more genes than the common NF1 microdeletions) and the 7qter duplication were not accompanied by unexpected clinical features. Most likely the 7qter trisomy and the 17q11.2 microdeletion coincide by chance in our patient.

Immunity to killer toxin K1 is connected with the Golgi-to-vacuole protein degradation pathway.

Killer strains of Saccharomyces cerevisiae producing killer toxin K1 kill sensitive cells but are resistant to their own toxin. It is assumed that in the producer, an effective interaction between the external toxin and its plasma membrane receptor or the final effector is not possible on the grounds of a conformation change of the receptor or its absence in a membrane. Therefore, it is possible that some mutants with defects in intracellular protein transport and degradation can show a suicidal phenotype during K1 toxin production. We have examined these mutants in a collection of S. cerevisiae strains with deletions in various genes transformed by the pYX213+M1 vector carrying cDNA coding for the K1 toxin under the control of the GAL1 promoter. Determination of the quantity of dead cells in colony population showed that (1) the toxin production from the vector did not support full immunity of producing cells, (2) the suicidal phenotype was not connected with a defect in endocytosis or autophagy, (3) deletants in genes VPS1, VPS23, VPS51 and VAC8 required for the protein degradation pathway between the Golgi body and the vacuole exhibited the highest mortality. These results suggest that interacting molecule(s) on the plasma membrane in the producer might be diverted from the secretion pathway to degradation in the vacuole.

[Case reports of patients with a marker chromosome]. / Kazuistiky pacientu s marker chromozómy.

Small, usually supernumerary chromosomes, denoted as marker chromosomes or markers, can be represented by various phenotypic expression, that depends on their origin and extent. Our article presents results of molecular cytogenetic analysis (FISH) of 34 patients with identified marker chromosome. In 21 cases a marker derived from acrocentric chromosome was identified, in 9 cases markers of gonosomal origin [der(X), der(Y)], and in 4 patients markers of some other chromosomes (5, 17, 18) were proved. The most frequent marker was that originating from chromosome 15 (8 cases). Two patients with different phenotype, markedly influenced by the extent of pseudoizodicentric chromosome 15 are described. In accordance with hitherto presented data, presence of supernumerary copies of the critical region PWACR (it is the partial trisomy, resp. tetrasomy 15q11-q13) in majority of cases brings about serious affection described as syndrome of the inverted duplication of chromosome 15. The most typical symptoms are psychomotoric retardation, hypotony, neurological symptoms and autistic features. The article stresses the importance of FISH method in the prenatal examination of marker chromosomes.

Secondary pseudohypoaldosteronism in an infant with pyelonephritis.

BACKGROUND: Urinary tract infections and/or urinary tract anomalies are very frequent among children. Especially in newborns/infants they represent additional factors in the development of secondary pseudohypoaldosteronism. CASE HISTORY: We present an 8-week-old infant who developed hyponatremia and hyperkalemia secondary to acute pyelonephritis. The boy presented with non-specific signs, including poor appetite, lethargy, and hypotonia. An extended evaluation led to the diagnosis of pseudohypoaldosteronism (PHA). PHA was transient and during therapy of pyelonephritis all of abnormal laboratory parameters returned to normal. The patient had vesico-ureteric reflux grade IV. CONCLUSION: Secondary/transient/reversible PHA occurs in patients with immature renal tubular responsiveness to aldosterone due to infancy when they have urinary tract anomalies and/or urinary tract infection. (Tab. 1, Ref. 7.)

Changes in plasma membrane fluidity lower the sensitivity of S. cerevisiae to killer toxin K1.

The possible correlation between plasma membrane fluidity changes induced by modified cultivation conditions and cell sensitivity to the killer toxin K1 of Saccharomyces cerevisiae were investigated. Cells grown under standard conditions exhibited high toxin sensitivity. Both a membrane fluidity drop and fluidity rise brought about markedly reduced sensitivity to the toxin. These results do not fit the hypothesis of physiological relevance of direct toxin-lipid interaction, suggesting that the essential event in killer toxin action is interaction with membrane protein(s) that can be negatively influenced by any changes of membrane fluidity.

[Genetic study of 20 patients with autism disorders]. / Genetická studie dvaceti pacientu s poruchami autistického spektra.

BACKGROUND: Many observations indicate that genetic factors play an important role in the aetiology of autism. Up to now, however, no genetic markers have been convincingly identified which influence the predisposition to this disorder. Complex genetic analysis of autistic patients and their families may therefore lead to the identification of features which could help to direct further search for the predisposing genes. METHODS AND RESULTS: We have analysed a sample of 20 patients with autism spectrum disorders. The patients have been subjected to clinical genetic examination, cytogenetic analysis and DNA analysis of the FMR1 gene. In the sample studied we have observed more boys (15/20), various degree of mental retardation (18/20), high frequency of complications during pregnancy (10/20) and delivery (10/20), increased incidence of psychiatric disorders, behavioural abnormalities and suicides among the relatives, and increased head circumference and unusually formed ears in the probands. Three patients had different chromosomal aberrations or variants (t(21;22), inv(9) and inv(10)). One patient harboured expansion of the trinucleotide repeat sequence in the FMR1 gene on the full mutation level which is characteristic for the fragile X syndrome, and one patient is suspected to suffer from the Rett syndrome. CONCLUSIONS: Our observations confirm and extend the results reported in the literature. Most interesting are mainly the macrocephaly which may be associated with the recently described increased neonatal levels of neural growth factors in autistic individuals, ear malformations which may indicate aberrations in the HOXA1 gene pathway, the occurrence of chromosomal inversions recurrent in autism, and peculiarities in the pedigrees of the patients.

[Chromosome analysis in medicine]. / Chromozomální vysetrení v medicíne.

Aberrations of the normal number and structure of chromosomes can cause mental, growth and developmental delay, defects of sexual development, congenital defects, abnormal facial features, deformation of extremities, defective intrauterine development, spontaneous miscarriages, and infertility. Expressive changes of the karyotype are used to be found in cancer cells. In majority of cases a lot of genes are abundant or deleted and then many organs are affected--therefore disorders are described as "syndromes". Down and Turner syndromes are the best known syndromes caused by numerical aberrations of human chromosomes. In the diagnostics of structural aberrations, the use of methods of classical cytogenetics becomes limited. Fluorescence in situ hybridisation (FISH) is therefore used more frequently. FISH method has several advantages: rapidity, sensitivity, specificity and possibility to apply this method also in interphase nuclei. Application of FISH allows us to detect submicroscopic deletions and amplifications and to explain the aetiology of inborn developmental defects and cancer diseases (including familiar cases). The newest FISH modifications perform one step analysis of multiple chromosomal rearrangements and help us to ascertain the diagnosis and the prognosis of cancer diseases. The use of special computer software for chromosomal and FISH analysis is the most important part of the current cytogenetic diagnostics.

[Medical genetics in reproductive medicine]. / Vyuzití lékarské genetiky v reprodukcní medicíne.

Reproductive genetics (RG) is another new field of medical genetics, integrated with reproductive medicine, assisted reproduction and developmental genetic. RG is closely linked to the perioconceptional prevention, perinatology, ultrasound and biochemical screening in the end of the first and beginning of the second trimesters. RG is based on the system of specialized genetic counseling, clinical cytogenetics, molecular cytogenetics and molecular genetics to provide prefertilization, preimplantation and classical prenatal diagnosis in the Ist to IIIrd trimesters. Thus, RG is part of the fetal medicine and therapy. The six years experience with RG is summarized. A system of the specialized health care, organized, if possible in one integrated center of RG and reproductive medicine (RM) is presented. Reproductive medicine provides all necessary clinical gynecological and andrological surveillance, with assisted reproduction and further obstetrical ultrasound examinations, including nuchal translucency measurements and 2D, 3D ultrasound, echocardiography examinations, if indicated, as well as the invasive method of prenatal diagnosis and perinatology care. Specialized genetic counseling and cytogenetic analysis, if indicated, should be offered to all partners with reproductive disorders as well as to oocyte donors. Chromosome anomalies are disclosed in 6% of men with abnormal sperm analysis as well as in women with severe reproductive disorders. In males with severe oligo, azoospermia, the sperm aneuploidy analysis by molecular cytogenetic methods is recommended. Advised is also the molecular genetic detection of Y chromosome microdeletions, which is detected in 9% of our azoospermic men with deletions in AZFb region. CFTR gene mutations and intron 8 and 10 polymorphism examination is provided not only in men with obstructive azoospermia (CBAVD), but also if severe oligospermy with less than 1 x 10(6) sperm/ml is detected. Molecular genetic analysis of thrombophilic mutations of factor II., V. (Leiden) and MTHFR gene in unexplained recurrent abortions and in cases with unsuccessful IVF is part of the diagnostic strategy. The population frequencies of carriers of mutations of factor II. (2.3%), factor V.-Leiden (5.7%) and MTHFR gene (38%) were determined. The laser biopsy of the first polar body and of blastomeres was introduced for FISH analysis of chromosome aneuploidies. Quantitative fluorescent PCR (QFPCR) detection is used for testing of the most frequent delta F508 CFTR gene mutation and the most frequent aneuploidies of chromosome 13, 18, 21, X and Y. QFPCR was successfully tested for male fetal sex examination from partially purified fetal cells in the maternal blood. The first trimester ultrasound and biochemical screening is recommended to all successful pregnancies after different IVF methods. If borderline levels of first trimester biochemical screening of PAPP-A protein and beta hCG are detected without pathological ultrasound findings, classical triple test of biochemical screening in 16th week of gestation is recommended. If pathological results of ultrasound and biochemical screening are disclosed, invasive prenatal genetic diagnosis is indicated as well as in pregnancies after ICSL, if there is not any obstetrical contraindication.

[Adult height of patients after long-term treatment of idiopathic growth hormone deficiency. (Czech Registry 1991-1998)]. / Dospelá výska pacientu dlouhodobe lécených pro idiopatický deficit rustového hormonu (Ceský registr 1991-1998).

BACKGROUND: Final height was evaluated in patients from the Czech Register with idiopathic growth hormone deficiency treated with GH. METHODS AND RESULTS: 23 patients had the isolated growth hormone deficiency (group 1), and 37 suffered from multiple pituitary hormones deficiencies (group 2). The patients from group 1 and 2 were given growth hormone for 6.7 +/- 2.2 years and 9.6 +/- 3.0 years, respectively. The patients with isolated growth hormone deficiency reached final height -1.4 +/- 1.3 SDS, those with multiple hormone deficiencies were taller (-0.7 +/- 1.5 SDS). The height gain equalled +2.5 +/- 0.6 SDS and +3.4 +/- 1.1 SDS in group 1 and 2, respectively. 70% of the patients in group 1 and 93% of group 2 reached final heights within the target limits (+/- 2 SDS). CONCLUSION: The final height positively correlated with the target height (mid-parental height) and height at the onset of puberty (group 1 and 2). There was a negative correlation between the final height and the chronological age at the beginning of growth hormone therapy in group 1.

[A dissecting aortic aneurysm in a female patient with Turner syndrome]. / Disekující aneuryzma aorty u nemocné s Turnerovým syndromem.

Female phenotype, sexual infantilism, small stature and stigmatization are typical for patients with Turner's syndrome (TS). The most frequent cardiovascular manifestations in these patients are a bicuspidal aortal valve and coarctation of the aorta. In 5% patients dilatation of the aorta is found which can develop into a dissecting aneurysm. In the submitted case-history the authors describe a 34-year-old patient where the diagnosis of TS was proved only in adult age at the time when a dissecting aneurysm of the aorta was detected. The submitted case-history supports the recommendation of regular echocardiographic check-up examinations of patients with TS.

[Experiences in CSR with rapid diagnostic tests in diagnosis of bacterial meningitis]. / Erfahrungen in der CSR mit schnelldiagnostischen Tests bei der Diagnose bakterieller Meningitiden.

On the basis of examinations of 229 children with rapid diagnostic method--latex agglutination of cerebrospinal fluid, serum and urine--this method is to compare with classic culture and it is evaluated as advantageous in the clinical practice. The etiologic agents was found out in 199 cases with the help of latex agglutination.