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.

Refined histopathological predictors of BRCA1 and BRCA2 mutation status: a large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia.

INTRODUCTION: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling. METHODS: Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the likelihood of mutation status by histopathological markers were derived using a Mantel-Haenszel approach. RESULTS: ER-positive phenotype negatively predicted BRCA1 mutation status, irrespective of grade (LRs from 0.08 to 0.90). ER-negative grade 3 histopathology was more predictive of positive BRCA1 mutation status in women 50 years or older (LR = 4.13 (3.70 to 4.62)) versus younger than 50 years (LR = 3.16 (2.96 to 3.37)). For BRCA2, ER-positive grade 3 phenotype modestly predicted positive mutation status irrespective of age (LR = 1.7-fold), whereas ER-negative grade 3 features modestly predicted positive mutation status at 50 years or older (LR = 1.54 (1.27 to 1.88)). Triple-negative tumor status was highly predictive of BRCA1 mutation status for women younger than 50 years (LR = 3.73 (3.43 to 4.05)) and 50 years or older (LR = 4.41 (3.86 to 5.04)), and modestly predictive of positive BRCA2 mutation status in women 50 years or older (LR = 1.79 (1.42 to 2.24)). CONCLUSIONS: These results refine likelihood-ratio estimates for predicting BRCA1 and BRCA2 mutation status by using commonly measured histopathological features. Age at diagnosis is an important variable for most analyses, and grade is more informative than ER status for BRCA2 mutation carrier prediction. The estimates will improve BRCA1 and BRCA2 variant classification and inform patient mutation testing and clinical management.

ZC4H2 mutations are associated with arthrogryposis multiplex congenita and intellectual disability through impairment of central and peripheral synaptic plasticity.

Arthrogryposis multiplex congenita (AMC) is caused by heterogeneous pathologies leading to multiple antenatal joint contractures through fetal akinesia. Understanding the pathophysiology of this disorder is important for clinical care of the affected individuals and genetic counseling of the families. We thus aimed to establish the genetic basis of an AMC subtype that is associated with multiple dysmorphic features and intellectual disability (ID). We used haplotype analysis, next-generation sequencing, array comparative genomic hybridization, and chromosome breakpoint mapping to identify the pathogenic mutations in families and simplex cases. Suspected disease variants were verified by cosegregation analysis. We identified disease-causing mutations in the zinc-finger gene ZC4H2 in four families affected by X-linked AMC plus ID and one family affected by cerebral palsy. Several heterozygous females were also affected, but to a lesser degree. Furthermore, we found two ZC4H2 deletions and one rearrangement in two female and one male unrelated simplex cases, respectively. In mouse primary hippocampal neurons, transiently produced ZC4H2 localized to the postsynaptic compartment of excitatory synapses, and the altered protein influenced dendritic spine density. In zebrafish, antisense-morpholino-mediated zc4h2 knockdown caused abnormal swimming and impaired α-motoneuron development. All missense mutations identified herein failed to rescue the swimming defect of zebrafish morphants. We conclude that ZC4H2 point mutations, rearrangements, and small deletions cause a clinically variable broad-spectrum neurodevelopmental disorder of the central and peripheral nervous systems in both familial and simplex cases of both sexes. Our results highlight the importance of ZC4H2 for genetic testing of individuals presenting with ID plus muscle weakness and minor or major forms of AMC.

The risk of contralateral breast cancer in patients from BRCA1/2 negative high risk families as compared to patients from BRCA1 or BRCA2 positive families: a retrospective cohort study.

INTRODUCTION: While it has been reported that the risk of contralateral breast cancer in patients from BRCA1 or BRCA2 positive families is elevated, little is known about contralateral breast cancer risk in patients from high risk families that tested negative for BRCA1/2 mutations. METHODS: A retrospective, multicenter cohort study was performed from 1996 to 2011 and comprised 6,235 women with unilateral breast cancer from 6,230 high risk families that had tested positive for BRCA1 (n = 1,154) or BRCA2 (n = 575) mutations or tested negative (n = 4,501). Cumulative contralateral breast cancer risks were calculated using the Kaplan-Meier product-limit method and were compared between groups using the log-rank test. Cox regression analysis was applied to assess the impact of the age at first breast cancer and the familial history stratified by mutation status. RESULTS: The cumulative risk of contralateral breast cancer 25 years after first breast cancer was 44.1% (95%CI, 37.6% to 50.6%) for patients from BRCA1 positive families, 33.5% (95%CI, 22.4% to 44.7%) for patients from BRCA2 positive families and 17.2% (95%CI, 14.5% to 19.9%) for patients from families that tested negative for BRCA1/2 mutations. Younger age at first breast cancer was associated with a higher risk of contralateral breast cancer. For women who had their first breast cancer before the age of 40 years, the cumulative risk of contralateral breast cancer after 25 years was 55.1% for BRCA1, 38.4% for BRCA2, and 28.4% for patients from BRCA1/2 negative families. If the first breast cancer was diagnosed at the age of 50 or later, 25-year cumulative risks were 21.6% for BRCA1, 15.5% for BRCA2, and 12.9% for BRCA1/2 negative families. CONCLUSIONS: Contralateral breast cancer risk in patients from high risk families that tested negative for BRCA1/2 mutations is similar to the risk in patients with sporadic breast cancer. Thus, the mutation status should guide decision making for contralateral mastectomy.

Constitutive promoter methylation of BRCA1 and RAD51C in patients with familial ovarian cancer and early-onset sporadic breast cancer.

Genetic defects in breast cancer (BC) susceptibility genes, most importantly BRCA1 and BRCA2, account for ~40% of hereditary BC and ovarian cancer (OC). Little is known about the contribution of constitutive (soma-wide) epimutations to the remaining cases. We developed bisulfite pyrosequencing assays to screen >600 affected BRCA1/BRCA2 mutation-negative patients from the German Consortium for Hereditary Breast and Ovarian Cancer for constitutive hypermethylation of ATM, BRCA1, BRCA2, RAD51C, PTEN and TP53 in blood cells. In a second step, patients with ≥6% promoter methylation were analyzed by bisulfite plasmid sequencing to demonstrate the presence of hypermethylated alleles (epimutations), indicative of epigenetic gene silencing. Altogether we identified nine (1.4%) patients with constitutive BRCA1 and three (0.5%) with RAD51C hypermethylation. Epimutations were found in both sporadic cases, in particular in 2 (5.5%) of 37 patients with early-onset BC, and familial cases, in particular 4 (10%) of 39 patients with OC. Hypermethylation was always confined to one of the two parental alleles in a subset (12-40%) of the analyzed cells. Because epimutations occurred in cell types from different embryonal layers, they most likely originated in single cells during early somatic development. We propose that analogous to germline genetic mutations constitutive epimutations may serve as the first hit of tumor development. Because the role of constitutive epimutations in cancer development is likely to be largely underestimated, future strategies for effective testing of susceptibility to BC and OC should include an epimutation screen.

Association of death receptor 4 variant (683A > C) with ovarian cancer risk in BRCA1 mutation carriers.

Dysregulation of apoptosis plays an important role in carcinogenesis. Therefore, apoptosis-associated genes like the death receptor 4 (DR4, TRAIL-R1) are interesting candidates for modifying the penetrance of breast and ovarian cancer in carriers of BRCA1 and BRCA2 mutations. The DR-4 haplotype 626C-683C [626C > G, Thr209Arg (rs4871857) and 683A > C, Glu228Ala (rs17088993)] has recently been linked to an increased risk of breast cancer. To evaluate whether DR4 626C > G or DR4 683A > C modifies the risk of breast or ovarian cancer in carriers of BRCA1 and BRCA2 mutations, we undertook a national multicenter study including data of 840 carriers of breast cancer gene (BRCA) mutations. DNA samples were collected from 12 German research centers between 1996 and 2005 and were genotyped by the Taqman allelic discrimination assay. The association between genotypes and incidence of breast or ovarian cancer data was evaluated using a Cox proportional hazards regression model. We found evidence for a significant association of DR4 683A > C with a higher risk for ovarian cancer in carriers of BRCA1 mutations [n = 557, hazard ratio 1.78 (1.24-2.55), p = 0.009]. Our results thus indicate that the DR4 683A > C variant modifies the risk of ovarian cancer in carriers of BRCA1 mutations.

Hb Riesa or ß93 (F9) Cys→Ser, a new electrophoretically silent haemoglobin variant interfering with haemoglobin A1c measurement.

A new ß variant was found in a German diabetic patient whose blood samples appeared to contain 45% Hb A(1c) using Bio-Rad Variant V-II A1c-analyzer but 7.6% on boronate affinity chromatography. Structural studies using, HPLC, mass spectrometry, and the genomic DNA analysis revealed a new substitution in which the cysteine residue at position ß93 was replaced by serine. The variant was named Hb Riesa or ß93 (F9) Cys→Ser and accounted for 54.3% of the total haemoglobin. This suggests that the protein-synthesis processes for the mutant could be slightly more promoted than those of the wild-type. Hb Riesa is clinically and electrophoretically silent.

Sweating ability and genotype in individuals with X-linked hypohidrotic ectodermal dysplasia.

BACKGROUND: X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common type of ectodermal dysplasia, is caused by EDA gene mutations. Reduced sweating contributes substantially to XLHED associated morbidity and mortality. To characterise the genotype-phenotype relationship, sweat gland function was assessed non-invasively in XLHED patients and healthy controls. SUBJECTS AND METHODS: In 36 genotyped XLHED patients and 29 control subjects aged 0-57 years, pilocarpine-induced sweat volume, palmar sweat pore density, and palmar skin conductance before and after stimulation were determined. RESULTS: Among 31 XLHED males, 14 had neither detectable sweat pores nor inducible sweating, 10 showed a few sweat pores but absent sweating, and 7 produced reduced sweat volumes (1-11 µl) as compared with controls (38-93 µl). Two of the low sweating XLHED subjects had normal sweat pore counts. In all 5 heterozygous females, some sweat was detected, but generally less than in female controls. Basal and stimulated skin conductance readings were reduced in 23 of 24 non-sweating, but only in 3 of 12 low-sweating XLHED subjects. There was no correlation between sweat production and number of missing teeth. CONCLUSIONS: In contrast to prior reports on non-genotyped hypohidrotic ectodermal dysplasia populations, this study confirmed a consistent, quantifiable defect of sweat gland function in male XLHED subjects as a disease biomarker. Among 26 different EDA genotypes, specific mutations were shown to be consistently associated with anhidrosis, implying that systematic mapping of EDA mutations together with the analysis of objective clinical data may help to distinguish functionally crucial mutations from those allowing residual activity of the gene product.

Association of the variants CASP8 D302H and CASP10 V410I with breast and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: The genes caspase-8 (CASP8) and caspase-10 (CASP10) functionally cooperate and play a key role in the initiation of apoptosis. Suppression of apoptosis is one of the major mechanisms underlying the origin and progression of cancer. Previous case-control studies have indicated that the polymorphisms CASP8 D302H and CASP10 V410I are associated with a reduced risk of breast cancer in the general population. METHODS: To evaluate whether the CASP8 D302H (CASP10 V410I) polymorphisms modify breast or ovarian cancer risk in BRCA1 and BRCA2 mutation carriers, we analyzed 7,353 (7,227) subjects of white European origin provided by 19 (18) study groups that participate in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A weighted cohort approach was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). RESULTS: The minor allele of CASP8 D302H was significantly associated with a reduced risk of breast cancer (per-allele HR, 0.85; 95% CI, 0.76-0.97; P(trend) = 0.011) and ovarian cancer (per-allele HR, 0.69; 95% CI, 0.53-0.89; P(trend) = 0.004) for BRCA1 but not for BRCA2 mutation carriers. The CASP10 V410I polymorphism was not associated with breast or ovarian cancer risk for BRCA1 or BRCA2 mutation carriers. CONCLUSIONS: CASP8 D302H decreases breast and ovarian cancer risk for BRCA1 mutation carriers but not for BRCA2 mutation carriers. IMPACT: The combined application of these and other recently identified genetic risk modifiers could in the future allow better individual risk calculation and could aid in the individualized counseling and decision making with respect to preventive options in BRCA1 mutation carriers.

Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers.

PURPOSE: To estimate the risk for contralateral breast cancer in members of BRCA1- and BRCA2-positive families and to determine predictive risk factors. PATIENTS AND METHODS: A retrospective, multicenter, cohort study was performed from 1996 until 2008 and comprised 2,020 women with unilateral breast cancer (index patients, n = 978; relatives, n = 1.42) from 978 families who had a BRCA1 or BRCA2 mutation. Cox regression analysis was applied to assess the association of age at first breast cancer with time from first to contralateral breast cancer, stratified by the affected BRCA gene. RESULTS: The cumulative risk for contralateral breast cancer 25 years after first breast cancer was 47.4% (95% CI, 38.8% to 56.0%) for patients from families with BRCA1 or BRCA2 mutations. Members of families with BRCA1 mutations had a 1.6-fold (95% CI, 1.2-fold to 2.3-fold) higher risk of contralateral breast cancer than members of families with BRCA2 mutations. Younger age at first breast cancer was associated with a significantly higher risk of contralateral breast cancer in patients with BRCA1 mutation, and a trend was observed in patients with BRCA2 mutation. After 25 years, 62.9% (95% CI, 50.4% to 75.4%) of patients with BRCA1 mutation who were younger than 40 years of age at first breast cancer developed contralateral breast cancer, compared with only 19.6% (95% CI, 5.3% to 33.9%) of those who were older than 50 years of age at first breast cancer. CONCLUSION: Contralateral breast cancer risk depends on age at first breast cancer and on the affected BRCA gene, and this risk should be considered in treatment planning.

Haemoglobin Noah Mehmet Oeztuerk (alpha(2) delta(2)143 (H21)His-->Tyr: A novel delta-chain variant in the 2,3-DPG binding site.

A new delta-chain variant, delta143 (H21) His-->Tyr or Hb Noah Mehmet Oeztuerk, was discovered during the investigation of the cause of hemolytic anaemia in a 6-month-old infant of Turkish descent. It was detected by Cation exchange high-performance liquid chromatography (CE-HPLC) using PolyCAT A column. P(50) was 20.6+/-0.60 mmHg and 29.3+/-0.40 mmHg for the carrier and the wild-type, respectively. This suggests an increase in oxygen affinity. On routine CE-HPLC Hb A(2) was low (1.2%) and the variant was not detected. An extended family study revealed that the variant was not associated with the anaemia or with any other clinical abnormality.

Haemoglobin Hokusetsu [beta52 (D3)] Asp-->Gly in German families associated with inclusion body.

Inclusion bodies associated with Hb Hokusetsu have never been published. We investigated the autoxidation of this variant as a cause for the inclusion bodies in three unrelated families. Moreover, haplotype analysis was carried out to unravel the origin of this variant also found in the Japanese population. The presence of inclusion bodies was revealed by incubating the fresh peripheral blood with brilliant cresyl blue. We further characterised this variant using mass spectrometry and DNA analysis. The generation of superoxide radical (ROS) during the autoxidation was assayed by electron spin resonance spectrometry. Inclusion bodies were seen in about 25% of red cells. Hb Hokusetsu turned out to be less thermostable than the control. It showed a tenfold-enhanced ROS formation versus control. The analysis of the beta-globin haplotypes for the three unrelated families showed that Hb Hokosetsu was linked with haplotype I (5' + - - - - + + 3'). This is the first case published in the German population. The inclusion bodies could be due to the instability of the variant. This is supported by the increased autoxidation. The absence of anaemia evokes an elimination of the inclusion bodies by the proteolytic mechanism of the red cells. The association of the variant in three unrelated families with the five polymorphisms of haplotype I indicates a single common mutation event. In the presence of Hb Hokusetsu, HbA 1C standard methods used to assess glycaemic control are mistaken.

Gross rearrangements in BRCA1 but not BRCA2 play a notable role in predisposition to breast and ovarian cancer in high-risk families of German origin.

A total of 226 index cases from high-risk hereditary breast and ovarian cancer families of German origin who had tested negative for small nucleotide alterations in BRCA1 and BRCA2 were analyzed for gross genomic rearrangements at the two gene loci by the multiplex ligation-dependent probe amplification technique. Six large genomic alterations were identified in BRCA1, while no gross rearrangements were found in BRCA2. The six BRCA1 mutations included two novel mutations including a deletion of exon 5, and a deletion comprising exons 5-7, as well as three distinct gross alterations previously reported, including a deletion of exons 1A, 1B, and 2, two duplications of exon 13, and a deletion of exon 17. To understand the mechanisms underlying the genomic rearrangements within the BRCA1 gene and to provide a simple PCR-based assay for further diagnostic applications, we have defined the molecular breakpoints of the deletion/insertion mutations. In all cases, our data point to a mechanism by which illegitimate crossing over between stretches of direct repeat sequences as small as 9 base pairs (bp) and up to 188 bp may have occurred. Overall, we provide evidence that gross rearrangements within the BRCA1 gene locus may be as frequent as 3% in primarily mutation-negative tested high-risk familial breast and ovarian cancer of German ancestry, while large alterations involving the BRCA2 locus do not appear to play a significant role in disease etiology. These findings have important implications for genetic counseling and testing of high-risk breast and ovarian cancer families.