Prevalence of Pathogenic Germline Variants in Women with Non-Familial Unilateral Triple-Negative Breast Cancer.

Introduction: International guidelines recommend genetic testing for women with familial breast cancer at an expected prevalence of pathogenic germline variants (PVs) of at least 10%. In a study sample of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), we have previously shown that women with TNBC diagnosed before the age of 50 years but without a family history of breast or ovarian cancer (sTNBC) meet this criterion. The present study investigates the PV prevalence in BRCA1, BRCA2, and nine additional cancer predisposition genes in an extended sTNBC study sample including a cohort of women with a later age at sTNBC diagnosis. Patients and Methods: In 1,600 women with sTNBC (median age at diagnosis: 41 years, range 19-78 years), we investigated the association between age at diagnosis and PV occurrence in cancer predisposition genes using logistic regression. Results: 260 sTNBC patients (16.2%) were found to have a PV in cancer predisposition genes (BRCA1: n = 170 [10.6%]; BRCA2: n = 46 [2.9%], other: n = 44 [2.8%]). The PV prevalence in women diagnosed between 50 and 59 years (n = 194) was 11.3% (22/194). Logistic regression showed a significant increase in PV prevalence with decreasing age at diagnosis (OR 1.41 per 10 years younger age at diagnosis; 95% confidence interval: 1.21-1.65; p < 0.001). The PV prevalence predicted by the model was above 10% for diagnoses before the age of 56.8 years. Conclusion: Based on the data presented, we recommend genetic testing by gene panel analysis for sTNBC patients diagnosed before the age of 60 years. Due to the still uncertain estimate for women with sTNBC diagnosed above the age of 60 years, further studies are needed.

Genetic Architecture of Azoospermia-Time to Advance the Standard of Care.

BACKGROUND: Crypto- and azoospermia (very few/no sperm in the semen) are main contributors to male factor infertility. Genetic causes for spermatogenic failure (SPGF) include Klinefelter syndrome and Y-chromosomal azoospermia factor microdeletions, and CFTR mutations for obstructive azoospermia (OA). However, the majority of cases remain unexplained because monogenic causes are not analysed. OBJECTIVE: To elucidate the monogenic contribution to azoospermia by prospective exome sequencing and strict application of recent clinical guidelines. DESIGN, SETTING, AND PARTICIPANTS: Since January 2017, we studied crypto- and azoospermic men without chromosomal aberrations and Y-chromosomal microdeletions attending the Centre of Reproductive Medicine and Andrology, Münster. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We performed exome sequencing in 647 men, analysed 60 genes having at least previous limited clinical validity, and strictly assessed variants according to clinical guidelines. RESULTS AND LIMITATIONS: Overall, 55 patients (8.5%) with diagnostic genetic variants were identified. Of these patients, 20 (3.1%) carried mutations in CFTR or ADGRG2, and were diagnosed with OA. In 35 patients (5.4%) with SPGF, mutations in 20 different genes were identified. According to ClinGen criteria, 19 of the SPGF genes now reach at least moderate clinical validity. As limitations, only one transcript per gene was considered, and the list of genes is increasing rapidly so cannot be exhaustive. CONCLUSIONS: The number of diagnostic genes in crypto-/azoospermia was almost doubled to 21 using exome-based analyses and clinical guidelines. Application of this procedure in routine diagnostics will significantly improve the diagnostic yield and clinical workup as the results indicate the success rate of testicular sperm extraction. PATIENT SUMMARY: When no sperm are found in the semen, a man cannot conceive naturally. The causes are often unknown, but genetics play a major role. We searched for genetic variants in a large group of patients and found causal mutations for one in 12 men; these predict the chances for fatherhood.

Expanding the spectrum of syndromic PPP2R3C-related XY gonadal dysgenesis to XX gonadal dysgenesis.

Homozygous variants in PPP2R3C have been reported to cause a syndromic 46,XY complete gonadal dysgenesis phenotype with extragonadal manifestations (GDRM, MIM# 618419) in patients from four unrelated families, whereas heterozygous variants have been linked to reduced fertility with teratozoospermia (SPGF36, MIM# 618420) in male carriers. We present eight patients from four unrelated families of Turkish and Indian descent with three different germline homozygous PPP2R3C variants including a novel in-frame duplication (c.639_647dupTTTCTACTC, p.Ser216_Tyr218dup). All patients exhibit recognizable facial dysmorphisms allowing gestalt diagnosis. In two 46,XX patients with hypergonadotropic hypogonadism and nonvisualized gonads, primary amenorrhea along with absence of secondary sexual characteristics and/or unique facial gestalt led to the diagnosis. 46,XY affected individuals displayed a spectrum of external genital phenotypes from ambiguous genitalia to complete female. We expand the spectrum of syndromic PPP2R3C-related XY gonadal dysgenesis to both XY and XX gonadal dysgenesis. Our findings supported neither ocular nor muscular involvement as major criteria of the syndrome. We also did not encounter infertility problems in the carriers. Since both XX and XY individuals were affected, we hypothesize that PPP2R3C is essential in the early signaling cascades controlling sex determination in humans.

Bi-allelic Mutations in M1AP Are a Frequent Cause of Meiotic Arrest and Severely Impaired Spermatogenesis Leading to Male Infertility.

Male infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meiotic arrest and identified the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 associated protein, in three unrelated men. This variant most likely results in a truncated protein as shown in vitro by heterologous expression of mutant M1AP. Next, we screened four large cohorts of infertile men and identified three additional individuals carrying homozygous c.676dup and three carrying combinations of this and other likely causal variants in M1AP. Moreover, a homozygous missense variant, c.1166C>T (p.Pro389Leu), segregated with infertility in five men from a consanguineous Turkish family. The common phenotype between all affected men was NOA, but occasionally spermatids and rarely a few spermatozoa in the semen were observed. A similar phenotype has been described for mice with disruption of M1ap. Collectively, these findings demonstrate that mutations in M1AP are a relatively frequent cause of autosomal recessive severe spermatogenic failure and male infertility with strong clinical validity.

Sequence Variants in TBX6 Are Associated with Disorders of the Müllerian Ducts: An Update.

Müllerian anomalies comprise the Mayer-Rokitansky-Küster-Hauser syndrome as well as fusion defects of the müllerian ducts. Recurrent micro-aberrations like deletions in 16p11.2 encompassing TBX6 were found to be causative in these patients. TBX6 encodes a transcription factor which plays a role in paraxial mesoderm differentiation/specification. In previous studies, we and other groups found possibly pathogenic variants in TBX6 in patients with müllerian anomalies. Since we suggested TBX6 as a strong candidate, we performed sequential analysis of the TBX6 gene in additional 125 patients with müllerian anomalies, and 2 possibly pathogenic missense variants and 1 nonsense substitution in TBX6 in 4/125 patients were found. The missense variant c.484G>A, which we have described in a previous study, was reidentified but with no higher frequency as in our controls. We detected 3 possibly pathogenic variants in TBX6 and could show that the variant c.484G>A is not causative for disorders of the müllerian ducts in the non-Finnish European population. In summary, we present increasing evidence for association of variants in TBX6 with malformations of the müllerian ducts.

Search for altered imprinting marks in Mayer-Rokitansky-Küster-Hauser patients.

BACKGROUND: Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) is the second most common cause of primary amenorrhea and characterized by absence of the uterus and the upper part of the vagina. The etiology of MRKH is mainly unknown but a contribution of genomic alterations is probable. A molecular disturbance so far neglected in MRKH research is aberrant methylation at imprinted loci. In fact, MRKH has been reported in patients with the imprinting disorder Silver-Russell syndrome. METHODS: We report on a rare patient with MRKH and SRS due to an ICR1 hypomethylation in 11p15.5. On the basis of this observation we screened a large cohort of MRKH patients (n > 100) for aberrant methylation at nine imprinted loci. RESULTS: We failed to detect any epimutation, thus we conclude that imprinting defects at least at the currently known disease-relevant imprinted loci do not contribute to the isolated MRKH phenotype. However, it cannot be excluded that altered methylation marks at other loci are involved in the etiology of MRKH. CONCLUSION: The molecular basis for MRKH remains unclear in the majority of patients, but future studies on the association between MRKH and ICR1 hypomethylation/SRS will to enlighten the role of epigenetics in the etiology of MRKH.

Clinical and genetic aspects of Mayer-Rokitansky-Küster-Hauser syndrome.

The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome [MIM 277000] is characterised by the absence of a uterus and vagina in otherwise phenotypically normal women with karyotype 46,XX. Clinically, the MRKH can be subdivided into two subtypes: an isolated or type I form can be delineated from a type II form, which is characterised by extragenital malformations. The so-called Müllerian hypoplasia, renal agenesis, cervicothoracic somite dysplasia (MURCS) association can be seen as the most severe phenotypic outcome. The MRKH syndrome affects at least 1 in 4000 to 5000 female new-borns. Although most of the cases are sporadic, familial clustering has also been described, indicating a genetic cause of the disease. However, the mode of inheritance is autosomal-dominant inheritance with reduced penetrance. High-resolution array-CGH and MLPA analysis revealed recurrent aberrations in different chromosomal regions such as TAR susceptibility locus in 1q21.1, chromosomal regions 16p11.2, and 17q12 and 22q11.21 microduplication and -deletion regions in patients with MRKH. Sequential analysis of the genes LHX1, TBX6 and RBM8A, which are located in chromosomal regions 17q12, 16p11.2 and 1q21.1, yielded in the detection of MRKH-associated mutations. In a subgroup of patients with signs of hyperandrogenaemia mutations of WNT4 have been found to be causative. Analysis of another member of the WNT family, WNT9B, resulted in the detection of some causative mutations in MRKH patients.

Four Novel NR5A1 Mutations in 46,XY Gonadal Dysgenesis Patients Including Frameshift Mutations with Altered Subcellular SF-1 Localization.

46,XY gonadal dysgenesis (46,XY GD) is a disorder of sexual development caused by mutations in genes involved in early gonadal development (bipotential gonads) and testis differentiation. In 46,XY GD individuals, mutations of the SRY gene are detected most frequently, followed by mutations in the NR5A1 (SF-1) gene, but in a lot of cases, the underlying molecular mechanism remains elusive. In this study, we retrospectively performed sequence analyses of the NR5A1 (SF-1) gene in 84 patients with complete, partial, and syndromic forms of 46,XY GD. In total, 7 heterozygous mutations were found in 6 of 84 patients (7.1%). Among these, we identified 4 mutations that, to the best of our knowledge, have not been reported before (c.268G>T, c.369del, c.871-1G>C, and c.893T>C). Transfection of different mutations revealed altered subcellular localization of the mutant SF-1 protein in the case of the frameshift mutations, indicating an impaired protein function. In conclusion, we present 4 novel mutations of the NR5A1 gene associated with 46,XY GD together with in vitro data pointing towards a possible functional impairment of the mutant SF-1 proteins.

New Territory for an Old Disease: 5-Alpha-Reductase Type 2 Deficiency in Bulgaria.

Disorders/differences of sexual development (DSD) are a group of conditions, some of which can be clinically indistinguishable mainly due to their phenotypic variability. Defining the molecular basis of their wide spectrum is still in progress. The diagnosis of 5-alpha-reductase type 2 (5α-reductase-2) deficiency is difficult especially in newborns and pre-pubertal individuals, and as a result its frequency might be underestimated. In the present study, we describe the clinical characteristics and molecular defects in 3 nonrelated 5α-reductase-2 deficiency patients of Bulgarian descent. Sequencing analysis revealed the mutations p.Y188CfsX9 and p.G196S, and MLPA analysis showed a deletion of exon 1 in the SRD5A2 gene. The observed genetic substitutions were not detected in 76 additionally screened unrelated controls, but a heterozygous healthy carrier of the p.R171S mutation was found. This is the first study on the molecular basis of 5α-reductase-2 deficiency in Bulgaria. It suggests that the carrier frequency of mutations in the SRD5A2 gene might be noteworthy worldwide. There is no correlation between cultural aspects, location, and/or population size and the number of different mutations in SRD5A2 detected, and more efforts should be made to determine the prevalence of this condition in different geographic areas. Our study supports the importance of genetic testing in 46,XY DSD patients, especially in countries or regions where 5α-reductase-2 deficiency has not been reported so far.

Variations in RBM8A and TBX6 are associated with disorders of the müllerian ducts.

OBJECTIVE: To identify genetic causes of malformations of the müllerian ducts. DESIGN: Retrospective laboratory study. SETTING: University hospital. PATIENT(S): A total of 167 patients with disorders of the müllerian ducts: 116 patients with Mayer-Rokitansky-Küster-Hauser syndrome and 51 patients with fusion disorders of the müllerian ducts. The control group was composed of 94 fertile women with at least one child. INTERVENTION(S): Sequential analysis of RBM8A and TBX6 in a group of 167 clinically well-defined patients with disorders of the müllerian ducts. MAIN OUTCOME MEASURE(S): Identification of rare variants in RBM8A and TBX6. RESULT(S): In total, we detected four RBM8A variants in 13 patients with disorders of the müllerian ducts and two heterozygous TBX6 variants in 5 of 167 patients. CONCLUSION(S): Mutations of RBM8A and TBX6 are associated with disorders of the müllerian ducts.

Premature ovarian failure caused by a heterozygous missense mutation in POF1B and a reciprocal translocation 46,X,t(X;3)(q21.1;q21.3).

In a patient affected by premature ovarian failure, a reciprocal translocation between chromosomes X and 3 and an additional heterozygous missense mutation in the X-linked gene POF1B were detected. Homozygosity for POF1B mutations is well-known to be associated with premature ovarian failure. In this case, the rare combination of skewed X inactivation due to the reciprocal translocation involving one X chromosome and heterozygosity for a known POF1B mutation explains the phenotype.

A Novel SRY Gene Mutation p.F109L in a 46,XY Female with Complete Gonadal Dysgenesis.

46,XY complete gonadal dysgenesis (CGD) is a disorder of sexual development that can result from different mutations in genes associated with sex determination. Patients are phenotypically females, and the disease is often diagnosed in late adolescence because of delayed puberty. Here, we present the clinical and molecular data of a 46,XY female CGD patient with gonadoblastoma with dysgerminoma and incidentally found inherited thrombophilia. The clinical significance of the described de novo SRY gene mutation c.325T>C (p.F109L) is discussed. This case report supports the critical role of the HGM domain in the SRY gene and the need of a multidisciplinary approach for CGD patients.

DMRT1 mutations are rarely associated with male infertility.

OBJECTIVE: To study a potential association between male infertility and DMRT1 mutations. DESIGN: Retrospective sequencing study. SETTING: University hospital. PATIENT(S): 171 patients with cryptozoospermia (sperm concentration<0.1 million/mL, n=40) or nonobstructive azoospermia (n=131), and 215 normozoospermic controls. INTERVENTION(S): Sequence analysis of DMRT1. MAIN OUTCOME MEASURE(S): Identification of rare variants in DMRT1 that are associated with male infertility. RESULT(S): In total, we detected four putative pathogenic mutations in six patients (3.5%) and less frequently in two controls (0.9%). CONCLUSION(S): Point mutations of DMRT1 may be rarely associated with male infertility.

Partial deletion of DMRT1 causes 46,XY ovotesticular disorder of sexual development.

OBJECTIVE: Ovotesticular disorder of sexual development (DSD) is an unusual form of DSD, characterized by the coexistence of testicular and ovarian tissue in the same individual. In a subset of patients, ovotesticular DSD is caused by 46,XX/46,XY chimerism or mosaicism. To date, only a few monogenetic causes are known to be associated with XX and XY ovotesticular DSD. DESIGN AND METHODS: Clinical, hormonal, and histopathological data, and results of high-resolution array-comparative genomic hybridization (CGH) were obtained from a female patient with 46,XY ovotesticular DSD with testicular tissue on one side and an ovary harboring germ cells on the other. Results obtained by array-CGH were confirmed by RT-quantitative PCR. RESULTS: We detected a deletion of ∼35 kb affecting exons 3 and 4 of the DMRT1 gene in a female patient with 46,XY ovotesticular DSD. To the best of our knowledge, this is the smallest deletion affecting DMRT1 presented to this point in time. CONCLUSIONS: We suggest that haploinsufficiency of DMRT1 is sufficient for both XY gonadal dysgenesis and XY ovotesticular DSD. Furthermore, array-CGH is a very useful tool in the molecular diagnosis of DSD.

Copy number variants in patients with severe oligozoospermia and Sertoli-cell-only syndrome.

A genetic origin is estimated in 30% of infertile men with the common phenotypes of oligo- or azoospermia, but the pathogenesis of spermatogenic failure remains frequently obscure. To determine the involvement of Copy Number Variants (CNVs) in the origin of male infertility, patients with idiopathic severe oligozoospermia (N = 89), Sertoli-cell-only syndrome (SCOS, N = 37)) and controls with normozoospermia (N = 100) were analysed by array-CGH using the 244A/400K array sets (Agilent Technologies). The mean number of CNVs and the amount of DNA gain/loss were comparable between all groups. Ten recurring CNVs were only found in patients with severe oligozoospermia, three only in SCOS and one CNV in both groups with spermatogenic failure but not in normozoospermic men. Sex-chromosomal, mostly private CNVs were significantly overrepresented in patients with SCOS. CNVs found several times in all groups were analysed in a case-control design and four additional candidate genes and two regions without known genes were associated with SCOS (P<1×10(-3)). In conclusion, by applying array-CGH to study male infertility for the first time, we provide a number of candidate genes possibly causing or being risk factors for the men's spermatogenic failure. The recurring, patient-specific and private, sex-chromosomal CNVs as well as those associated with SCOS are candidates for further, larger case-control and re-sequencing studies.

Recurrent aberrations identified by array-CGH in patients with Mayer-Rokitansky-Küster-Hauser syndrome.

OBJECTIVE: To identify genetic causes of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. DESIGN: Prospective laboratory study. SETTING: University hospital. PATIENT(S): Fifty-six patients with MRKH syndrome. INTERVENTION(S): Identification of microdeletions and -duplications in a group of 48 MRKH patients by array-CGH. Results obtained by array-CGH were confirmed by RT-qPCR. Sequential analysis of two candidate genes LHX1 and HNF1B in a group of 56 MRKH patients. MAIN OUTCOME MEASURE(S): Identification of chromosomal regions and genes (recurrent and private) associated with MRKH syndrome. RESULT(S): We could delineate three definitively relevant regions (1q21.1, 17q12, and 22q11.21) and suggest that LHX1 und HNF1B are candidate genes for MRKH syndrome, because we identified recurrent deletions affecting these genes and a possible causative missense mutation in LHX1. CONCLUSION(S): Our findings suggest that different chromosomal regions are associated with MRKH syndrome.

WNT10A mutations are a frequent cause of a broad spectrum of ectodermal dysplasias with sex-biased manifestation pattern in heterozygotes.

Odonto-onycho-dermal dysplasia (OODD), a rare autosomal-recessive inherited form of ectodermal dysplasia including severe oligodontia, nail dystrophy, palmoplantar hyperkeratosis, and hyperhidrosis, was recently shown to be caused by a homozygous nonsense WNT10A mutation in three consanguineous Lebanese families. Here, we report on 12 patients, from 11 unrelated families, with ectodermal dysplasia caused by five previously undescribed WNT10A mutations. In this study, we show that (1) WNT10A mutations cause not only OODD but also other forms of ectodermal dysplasia, reaching from apparently monosymptomatic severe oligodontia to Schöpf-Schulz-Passarge syndrome, which is so far considered a unique entity by the findings of numerous cysts along eyelid margins and the increased risk of benign and malignant skin tumors; (2) WNT10A mutations are a frequent cause of ectodermal dysplasia and were found in about 9% of an unselected patient cohort; (3) about half of the heterozygotes (53.8%) show a phenotype manifestation, including mainly tooth and nail anomalies, which was not reported before in OODD; and (4) heterozygotes show a sex-biased manifestation pattern, with a significantly higher proportion of tooth anomalies in males than in females, which may implicate gender-specific differences of WNT10A expression.

Prenatal diagnosis of Roberts syndrome and detection of an ESCO2 frameshift mutation in a Pakistani family.

OBJECTIVES: We report two siblings with Roberts syndrome (RBS), and an attempt to delineate the underlying molecular mechanism leading to familial recurrence. METHODS: Cytogenetic studies and direct sequencing of the ESCO2 gene were carried out in the second affected fetus and the parents. Fetal DNA was obtained from amniocytes after amniocentesis. Parental DNA was obtained from peripheral blood samples. RESULTS: Cytogenetic analysis of amniocytes revealed a normal male karyotype in 20 analyzed metaphases and chromosomal aneuploidies in 10 metaphases. All metaphases displayed premature separation of centromeres and puffing of heterochromatic regions near the centromere. A homozygous mutation leading to a frameshift in ESCO2 was identified in the fetal DNA sample. Both parents are heterozygous carriers of the same mutation. CONCLUSION: The present case demonstrates the prenatal diagnosis of RBS associated with a frameshift mutation in ESCO2.

BMP15 mutations in XX gonadal dysgenesis and premature ovarian failure.

OBJECTIVE: Premature ovarian failure (POF) is a heterogeneous group of diseases with amenorrhea before the age of 40 years and elevated gonadotropins. Recently, heterozygous mutations in the X-linked gene encoding bone morphogenetic protein-15 (BMP15) have been identified as a possible cause of ovarian failure. STUDY DESIGN: Molecular analysis of BMP15, growth differentiation factor-9 (GDF9), and follicle-stimulating hormone receptor (FSHR) in patients with ovarian failure. RESULTS: We can show that a BMP15 alteration, previously described as a mutation, is instead a polymorphism. A digenic inheritance of POF including BMP15 and FSHR is unlikely. Mutations in GDF9 could not be detected. CONCLUSION: Caution is recommended in the interpretation of BMP15 mutations in the context of POF.

Novel and recurrent mutations in patients with androgen insensitivity syndromes.

BACKGROUND/AIMS: Androgen insensitivity syndrome (AIS) caused by mutations within the androgen receptor gene represents a variety of phenotypes from females with 46,XY karyotype over individuals with ambiguous genitalia to infertile males. METHODS: We studied 24 patients with AIS by sequencing androgen receptor gene. 19 of the investigated patients were affected by complete androgen insensitivity syndrome (CAIS) and 5 suffered from partial androgen insensitivity syndrome (PAIS). RESULTS: So far we have detected 12 unreported mutations as well as 9 recurrent mutations (3 recurrent mutations were detected twice) in exons 2-8 of the androgen receptor gene. Three of the novel mutations cause a frameshift with subsequent premature termination and were found in patients with CAIS. These frameshifts were induced by single nucleotide deletion or insertion, or in one case by a 13-bp deletion, respectively. Another premature stop codon found in a CAIS patient results from an already reported nucleotide substitution in exon 5. Furthermore, in a CAIS patient we found a novel duplication of codon 788. All other mutations caused single base substitutions spread through exons 2-8 and were associated with CAIS or PAIS. CONCLUSIONS: We report a broad spectrum of different mutations within the AR gene leading to various manifestations of AIS. Apart from truncating mutations, a reliable genotype/phenotype correlation cannot be established. Therefore, modifying factors must be effective.