Array-comparative genomic hybridization analysis in patients with Müllerian fusion anomalies.

Fusion anomalies of the Müllerian ducts are associated with an increased risk for miscarriage and premature labor. In most cases polygenic-multifactorial inheritance can be assumed but autosomal-dominant inheritance with reduced penetrance and variable manifestation should be considered. We performed array-comparative genomic hybridization (CGH) analysis in a cohort of 103 patients with Müllerian fusion anomalies. In 8 patients we detected microdeletions and microduplications in chromosomal regions 17q12, 22q11.21, 9q33.1, 3q26.11 and 7q31.1. The rearrangement in 17q12 including LHX1 and HNF1ß as well as in 22q11.21 have already been observed in MRKHS (Mayer-Rokitansky-Küster-Hauser syndrome). In summary, we (1) detected causative micro-rearrangements in patients with Müllerian fusion anomalies, (2) show that Müllerian fusion anomalies and MRKHS may have a common etiology, and (3) identified new candidate genes for Müllerian fusion anomalies.

Mutations in WNT9B are associated with Mayer-Rokitansky-Küster-Hauser syndrome.

Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) is a well-known malformation pattern of the Müllerian ducts (MDs) characterized by congenital absence of the uterus and vagina. To date, most cases remain unexplained at molecular level. As female Wnt9b-/- mice show a MRKHS-like phenotype, WNT9B has emerged as a promising candidate gene for this disease. We performed retrospective sequence analyses of WNT9B in 226 female patients with disorders of the MDs, including 109 patients with MRKHS, as well as in 135 controls. One nonsense mutation and five likely pathogenic missense mutations were detected in WNT9B. Five of these mutations were found in cases with MRKHS accounting for 4.6% of the patients with this phenotype. No pathogenic mutations were detected in the control group (p = 0.017). Interestingly, all of the MRKHS patients with a WNT9B mutation were classified as MRKHS type 1, representing 8.5% of the cases from this subgroup. In previous studies, two of the patients with a WNT9B mutation were found to carry either an additional deletion of LHX1 or a missense mutation in TBX6. We conclude that mutations in WNT9B were frequently associated with MRKHS in our cohort and some cases may be explained by a digenic disease model.

[Genetic aspects of fertility disorders]. / Genetische Aspekte bei Störungen der Fertilität.

Genetic disorders of fertility can occur at the level of gonadal differentiation or function, germ cell production or function, and the genital ducts. In gonadal dysgenesis, the differentiation of testes or ovaries is impaired. Gonadal dysgenesis can be caused by chromosome aberrations or monogenetic defects in XY or XX gonadal dysgenesis. For the biosynthesis of sexual hormones, a normal development of the gonads and an intact hypothalamic-pituitary-gonadal axis is necessary. Disorders of steroid hormone synthesis are associated with an increased or diminished production of sexual hormones. Clinical and genetic aspects of adrenogenital syndrome are discussed here. Mutations of the androgen receptor cause a spectrum of androgen insensitivity ranging from women with female external genitalia through patients with genital ambiguity to men with infertility. Disturbed spermatogenesis is heterogeneous and can be the result of chromosome aberrations such as Klinefelter syndrome or structural aberrations as translocations and microdeletions of the Y chromosome. Premature ovarian failure is characterized by amenorrhea and hypergonadotropic hypogonadism before 40 years of age. Beside nongenetic factors, premature ovarian failure can be caused by chromosome aberrations or monogenetic defects. Disorders of the genital ducts such as anomalies of the müllerian ducts in females and of the wolffian ducts in males can be associated with sterility or infertility.

BRCA1/2 testing: uptake, phenocopies, and strategies to improve detection rates in initially negative families.

In families with clustering of breast and ovarian cancer, molecular testing of the major susceptibility genes BRCA1/2 helps to identify patients with disease mutations and healthy persons at high risk who can participate in targeted intervention programs. We investigated 5559 families from the German Consortium for Hereditary Breast and Ovarian Cancer included between 1997 and 2008 and treated under clinical routine conditions. In each family an index patient/person had been screened for deleterious mutations in BRCA1/2. Healthy relatives agreed to predictive testing in 888 of 1520 BRCA1/2 mutation-positive families (58%). Of 2646 eligible unaffected first-degree relatives 1143 decided to be tested (43%). In 325 families with BRCA1/2-positive index patients one related BC/OC patient was tested and 39 (12.0%; 95% confidence interval: 8.7-16.0%) discrepant cases found. A second related individual was screened in 163 of 3388 (4.9%) families with BRCA1/2-negative index patient and in eight families a BRCA1/2 mutation was found. In BRCA1/2 mutation-positive families, BC/OC patients lacking the familial mutation have to be expected at a rather high rate. In families with BRCA1/2-negative index patient we recommend a second screening if another patient with a high probability of carrying a BRCA1/2 mutation is available.

Frame shift mutation of LHX1 is associated with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome.

BACKGROUND: The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by congenital aplasia of the uterus and the upper part of the vagina in women who usually have normal ovaries and a 46, XX karyotype. MRKH can occur as an isolated form (type I) or in combination with various malformations as a syndromic or a type II MRKH. To date, in most of the cases the underlying etiology remains unclear. Recently, in approximately 6% of MRKH patients, deletions of chromosomal region 17q12 have been identified. The LHX1 gene, which is located in the deletion interval, has been suggested to be a strong candidate, because targeting inactivation of Lhx1 causes a complex phenotype including aplasia of the Müllerian ducts. METHODS AND RESULTS: By sequence analysis of LHX1 in a large cohort of MRKH patients, we detected a heterozygous frame shift mutation resulting in a premature stop codon. Previously, we have reported a heterozygous missense mutation of LHX1 in another MRKH patient. CONCLUSIONS: We conclude that heterozygous mutations of LHX1 might be one cause of the MRKH syndrome in a subgroup of patients.

Array-CGH analysis in patients with syndromic and non-syndromic XY gonadal dysgenesis: evaluation of array CGH as diagnostic tool and search for new candidate loci.

BACKGROUND: XY gonadal dysgenesis (XY-GD) is a heterogeneous disorder characterized by failure of testicular development despite a normal male karyotype. Non-syndromic and syndromic forms can be delineated. Currently, only a minority of cases can be explained by gene mutations. METHODS: The aim of this study was to detect microdeletions and duplications by using high-resolution Agilent oligonucleotide arrays in a cohort of 87 patients with syndromic or non-syndromic 46,XY-GD. RESULTS: In 26 patients, we identified gains or losses in regions including genes involved in XY-GD (DMRT1, SOX9, DAX1) or in regions, which have not been described as polymorphic copy number variants (CNVs). CONCLUSIONS: This study shows that array comparative genomic hybridization (CGH) analysis is a useful tool for the molecular diagnosis of XY-GD as well as for the identification of potential candidate genes involved in male sexual development.

Blood chimerism in a girl with Down syndrome and possible freemartin effect leading to aplasia of the Müllerian derivatives.

Cytogenetic and molecular genetic analysis in a case of sex-discordant dizygotic twins revealed blood chimerism in the girl (46,XY in blood and 47,XX, + 21 in fibroblasts) caused by feto-fetal transfusion from her healthy brother. The girl presented with Down syndrome, aplasia of the uterus and the Fallopian tubes and normal female external genitalia. We propose that the lack of Müllerian structures is caused by the effect of the Müllerian inhibiting substance transferred from the male to the female twin in early pregnancy. This disorder of sex development is known as freemartin phenomenon in female cattle from sex-discordant twin pairs.

Clinical spectrum of SIX3-associated mutations in holoprosencephaly: correlation between genotype, phenotype and function.

BACKGROUND: Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain. There are several important HPE mutational target genes, including the transcription factor SIX3, which encodes an early regulator of Shh, Wnt, Bmp and Nodal signalling expressed in the developing forebrain and eyes of all vertebrates. OBJECTIVE: To characterise genetic and clinical findings in patients with SIX3 mutations. METHODS: Patients with HPE and their family members were tested for mutations in HPE-associated genes and the genetic and clinical findings, including those for additional cases found in the literature, were analysed. The results were correlated with a mutation-specific functional assay in zebrafish. RESULTS: In a cohort of patients (n = 800) with HPE, SIX3 mutations were found in 4.7% of probands and additional cases were found through testing of relatives. In total, 138 cases of HPE were identified, 59 of whom had not previously been clinically presented. Mutations in SIX3 result in more severe HPE than in other cases of non-chromosomal, non-syndromic HPE. An over-representation of severe HPE was found in patients whose mutations confer greater loss of function, as measured by the functional zebrafish assay. The gender ratio in this combined set of patients was 1.5:1 (F:M) and maternal inheritance was almost twice as common as paternal. About 14% of SIX3 mutations in probands occur de novo. There is a wide intrafamilial clinical range of features and classical penetrance is estimated to be at least 62%. CONCLUSIONS: Our data suggest that SIX3 mutations result in relatively severe HPE and that there is a genotype-phenotype correlation, as shown by functional studies using animal models.

Variations of sex development: The first German interdisciplinary consensus paper.

INTRODUCTION: The term variations of sex development subsumes a large number of congenital conditions including chromosomal mosaics and variations of chromosomal, gonadal, and phenotypic sex. A situation of this nature may cause severe distress to both, parents and affected persons. One of the reasons for this is the binary form of gender classification in the society. In the past, because of a fear of possible stigmatization and an inability to cope with complex situations, it has been medical policy and practice for newborns to undergo early, mostly 'feminizing' elective surgery with the aim of achieving an outer genital appearance that is unambiguously male or female. Protests by advocacy groups for the most part as well as the results of outcome studies have shown that the development of affected persons may be very different to what has been expected and often does not result in the intended clear female or male gender identity as had been intended. It, therefore, seemed a matter of urgency to implement this new awareness as well as the ethical and personal human rights perspectives in the recommendations for the medical and psychosocial management of diverse sex development (DSD) in the future. STUDY DESIGN: In 2012, an interdisciplinary group of German academics engaged in the field of DSD decided to work on a consensus paper for this topic. It involved the participation of all faculties and non-scientific groups dealing with DSD, in particular advocacy and service-user groups. In a structured consensus, process recommendations were developed based on scientific literature as well as personal experiences of clinicians and affected individuals. RESULTS: Finally, 37 recommendations were agreed on. The strength of consensus is reflected in the degree of agreement as expressed in percentages. CONCLUSION: The introduction of the consensus paper reflects on the emerging paradigm shift and the necessity for a more open view of gender within society. The paper is intended to aid the performance of appropriate diagnostics in DSD-affected newborns and especially to help parents and affected persons cope with the biological and social consequences of DSD. With regard to medical or surgical therapy, it gives information about the most recent treatment trends.

Distribution of sex chromosomes in dysgenetic gonads of mixed type.

In a four-week-old child with female external and internal genitalia but with clitoris hypertrophy chromosome analysis from blood lymphocytes revealed a 46,XY karyotype. No deletion of Y chromosomal sequences was detected by PCR analysis of genomic DNA isolated from peripheral blood leucocytes. Because of the increased risk for gonadal tumours, gonadectomy was performed. Conventional cytogenetic analysis of the left dysgenetic gonad revealed a gonosomal mosaicism with a 45,X cell line in 27 of 50 metaphases. The dysgenetic left gonad demonstrated a significantly higher proportion (P = 0.005) of cells carrying a Y chromosome (46.3%) than the streak gonad from the right side (33.9%). Histomorphological examination of the left gonad revealed immature testicular tissue and rete-like structures as well as irregular ovarian type areas with cystic follicular structures. Interphase FISH analysis of the different tissues of this dysgenetic gonad demonstrated variable proportions of cells with an X and a Y chromosome. Whereas Sertoli cells and rete-like structures revealed a significantly higher proportion of XY cells in relation to the whole section of the dysgenetic gonad (P < 0.0001), almost all granulose-like cells carried no Y chromosome. The proportion of XY/X cells in theca-like cells and Leydig cells was similar to that of the whole dysgenetic gonad. In contrast to these findings, spermatogonia exclusively contained an XY constellation.

PLAG1 activation in lipoblastoma coinciding with low-level amplification of a derivative chromosome 8 with a deletion del(8)(q13q21.2).

Lipoblastoma is a benign uncommon soft-tissue-tumor resembling fetal adipose tissue affecting mainly children under three years of age. In lipoblastoma, the typical cytogenetic changes are clonal rearrangements involving chromosomal region 8q11-->q13. The oncogene PLAG1 (pleomorphic adenoma gene 1) is located within this chromosomal region on band 8q12. Recent reports have demonstrated that in lipoblastoma, the PLAG1 gene is activated by 'promoter-swapping'. Herein, we demonstrate that in lipoblastoma, the PLAG1 gene may also be activated by low-level amplification. We report on a lipoblastoma with the karyotype 48 approximately 50,XX,del(8)(q13q21.2),+del(8)(q13q21.2)x4[cp12]. Subsequent FISH analysis on uncultured tumor cells confirmed this result and demonstrated a low-level amplification of the chromosomal region 8pter-->8q13 and 8q21.2-->8qter. A partial monosomy was seen for the chromosomal region 8q13-->8q21.2. No other gains or losses were observed by CGH analysis. RT-PCR analysis showed that the PLAG1 gene is activated in the tumor sample of the lipoblastoma analyzed, in contrast to normal fatty tissue without PLAG1 expression. In conclusion, our results demonstrate that low-level amplification is a further mechanism of PLAG1 activation in lipoblastomas.

Cloning of Z39Ig, a novel gene with immunoglobulin-like domains located on human chromosome X.

The cDNA sequence and expression profile of a novel human gene, encoding a new member of the immunoglobulin superfamily, is reported. The gene is localized in the pericentromeric region of human X chromosome between the markers DXS1213 and DXS1194. Abundant expression of transcripts was detected in several human fetal tissues, whereas among adult tissues lung and placenta express highest levels of Z39Ig mRNA.

Genotype/phenotype correlation in a patient with partial monosomy 15 and partial trisomy 14.

We report on a girl with severe mental and psychomotor retardation caused by an unusual, unbalanced translocation t(14;15) of maternal origin. The unbalanced translocation in the patient resulted in trisomy 14pter-->q13 and monosomy 15pter-->q11.2. In addition to common features described in other patients with small proximal trisomies of chromosome 14, our patient presented with hypopigmented skin with light hair and eye color and severe speech impairment. Therefore the phenotype of the girl shows few similarities to that of Angelman syndrome patients, although the breakpoint in chromosome 15 in our patient was found to be proximal to the PWS/AS region.

Experts' Opinion on the Prenatal Therapy of Congenital Adrenal Hyperplasia (CAH) Due to 21-Hydroxylase Deficiency - Guideline of DGKED in cooperation with DGGG (S1-Level, AWMF Registry No. 174/013, July 2015).

Purpose: This guideline of the German Society of Pediatric Endocrinology and Diabetology (DGKED) is designed to be experts' opinion on the current concept of prenatal therapy for congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). Several scientific medical societies have also participated in the guideline. It aims to offer guidance to physicians when they counsel affected families about prenatal therapy. Methods: The experts commissioned by the medical societies developed a consensus in an informal process. The consensus was subsequently confirmed by the steering committees of the respective medical societies. Recommendations: Prenatal CAH therapy is an experimental therapy. We recommend designing and using standardized protocols for the prenatal diagnosis, therapy and long-term follow-up of women and children treated prenatally with dexamethasone. If long-term follow-up is not possible, then prenatal therapy should not be performed.

Multi-locus (ML)-FISH is a reliable tool for nondisjunction studies in human oocytes.

In the present study, we developed a fluorescence in situ hybridization (FISH) strategy, which allows a reliable determination of the chromatid number of specific chromosomes in mature human oocytes. 168 unfertilized oocytes were analyzed by dual-color FISH with two direct-labeled locus-specific DNA probes for chromosome 13 and 21. To exclude FISH failures, metaphases with abnormal signal patterns were reanalyzed by multi-locus-FISH (ML-FISH) for chromosome 13 and 21. Following dual-color FISH, abnormal signal patterns were detected in 21 out of 108 metaphases (19.4%). 17 of these metaphases were reanalyzed by ML-FISH. In contrast to the first FISH, seven metaphases showed normal signal patterns after rehybridization, whereas ten metaphases remained abnormal. Out of these real aneuploid metaphases, five showed gain or loss of a single signal (= chromatid), two showed missing double signals (= chromosome) and three showed both. In conclusion, locus-specific FISH probes facilitate differentiation between first meiotic nondisjunction of whole chromosomes and prematurely divided chromatids. Moreover, simultaneous hybridization with a second locus-specific probe on the same chromatid (ML-FISH) helps to differentiate between FISH failures and real meiotic division errors and therefore, allows a more reliable analysis of aneuploidies in human oocytes.

Mapping of a further locus for X-linked craniofrontonasal syndrome.

Craniofrontonasal syndrome is a rare dysostosis syndrome with an unusual pattern of X-linked inheritance, because males are usually not or less severely affected than females. Previously, a CFNS locus has been localised in Xp22. We report on a haplotype analysis in a German CFNS family, mapping the CFNS locus to the pericentromeric region of the X chromosome. This discrepancy can be explained by locus heterogeneity. Furthermore, random X inactivation could be demonstrated in affected females. The most plausible interpretation for this unusual pattern of X-linked inheritance is metabolic interference. Consequently, we propose that the CFNS gene escapes X inactivation.

Close linkage of the Wieacker-Wolff syndrome to the DNA segment DXYS1 in proximal Xq.

Linkage studies with RFLPs were performed in a large family in which the Wieacker-Wolff syndrome is segregating. In this new syndrome (McKusick, 1986, No. 31458) patients have congenital contractures, progressive neuropathic muscle atrophy, involving also some cranial nerves with oculomotor apraxia and dyspraxia of the face and tongue muscles, and mental retardation. This is an X-linked recessive syndrome. We found close linkage between the syndrome locus and the DNA segment DXYS1 (z = 3.225 at theta = 0.0) in proximal Xq.

A new X-linked syndrome with muscle atrophy, congenital contractures, and oculomotor apraxia.

Six men from three generations of one family had manifestations of a possible new syndrome. All had congenital contractures of the feet at birth, a slowly progressive predominantly distal muscle atrophy, dyspraxia of the eye, face, and tongue muscles, and mild mental retardation. The pedigree is compatible with X-linked recessive inheritance with no detectable manifestations in the obligate carriers. Linkage analysis excludes close linkage with the Xg locus and a polymorphic DNA sequence from the long arm of the X chromosome (DXS17).

A novel translocation (17;19)(p13;p13) in a patient with acute myelomonocytic leukemia.

We report on a patient with acute myeloid leukemia (AML M4) and a so far unrecorded translocation (17;19). The leukemia transformed from a myeloproliferative disorder (MPD) and showed a progressive fatal course. Following transformation, all leukemic cells showed an apparently balanced translocation (17;19)(p13;p13). The breakpoint regions harbor genes such as TP53 (17p13) and E2A, ENL, or LYL1 (19p13), which could be relevant in leukemogenesis. We suspect that the translocation (17;19)(p13;p13) may be a prognostic factor for transformation from chronic MPD to acute leukemia.

A(870)E mutation of the androgen receptor gene in a patient with complete androgen insensitivity syndrome and Sertoli cell tumor.

In a 60-year-old woman with complete androgen insensitivity syndrome (CAIS) and Sertoli cell tumor, a germline mutation (A870E) in exon 8 of the androgen receptor (AR) gene could be detected. A sister of the patient was also affected by CAIS and developed a Sertoli cell tumor at age 56. The mutation has not been described so far and could be seen in a causal relationship with the development of this tumor.