Family Pedigree Research Articles

Genetic Analysis Reveals Complete Androgen Insensitivity Syndrome in Female Children Surgically Treated for Inguinal Hernia

Background: Complete androgen insensitivity syndrome (CAIS) is a congenital condition caused by genetic defects in the androgen receptor (AR) gene located on the X chromosome, which lead to a phenotypical female individual with a 46, XY karyotype. Early diagnosis of CAIS is essential for proper clinical management, allows assessment of familial risk and contributes to healthcare decisions. However, diagnosis of CAIS can be overlooked in girls with inguinal hernia, resulting in inappropriate management. Methods: Five female patients from three unrelated families presented to our genetic clinic with primary amenorrhea. Each patient had been diagnosed with inguinal hernia in childhood and had undergone hernia repair without further investigation into what was contained in the hernial sac. We carried out physical examination, cytogenetic studies, hormonal evaluation, and molecular analysis to establish a comprehensive diagnosis. Family history and pedigree were collated to identify at-risk family members. Results: All patients presented with female external genitalia. Cytogenetic studies revealed a 46, XY karyotype and hormonal analysis suggested a diagnosis of CAIS. Sequencing of the AR gene in all patients and suspected family members revealed pathogenic variants in the AR gene and confirmed the molecular diagnosis of CAIS. Conclusions: We report the delayed diagnosis of CAIS in female Indonesian patients with a history of inguinal hernia in childhood. An early diagnosis of CAIS is essential for appropriate clinical management, as well as assessing familial risk. Increasing awareness among clinicians is paramount, and we encourage a CAIS diagnosis to be considered in any patient presenting with female appearance and inguinal hernia.

The histidine decarboxylase model of tic pathophysiology: a new focus on the histamine H3 receptor.

Histamine dysregulation was implicated as a rare cause of Tourette syndrome and other tic disorders a decade ago by a landmark genetic study in a high density family pedigree, which implicated a hypomorphic mutation in the histidine decarboxylase (Hdc) gene as a rare but high penetrance genetic cause. Studies in Hdc knockout (KO) mice have confirmed that this mutation causes tic-relevant behavioural and neurochemical abnormalities that parallel what is seen in patients and thus validate the KO as a potentially informative model of tic pathophysiology. Recent studies have focused on the potential role of the histamine H3 receptor in this model, and by association in tic disorders and related neuropsychiatric conditions. The H3 receptor is up-regulated in the striatum in Hdc KO mice. As the H3 receptor has constitutive activity in the absence of ligand, this receptor up-regulation may have significant cellular effects despite the absence of neurotransmitter histamine in these mice. Activation in vivo of H3 receptors in wild type mice regulates signalling in striatal medium spiny neurons (MSNs) that interacts non-linearly with dopamine receptor signalling. Baseline signalling alterations in MSNs in Hdc KO mice resemble those seen after H3 receptor agonist treatment in wild type animals. H3 receptor agonist treatment in the KOs further accentuates most of these signalling abnormalities and produces behavioural stereotypy. Together, these data suggest the intriguing hypothesis that constitutive signalling by up-regulated H3 receptors explains many of the molecular and behavioural abnormalities seen in these animals. LINKED ARTICLES: This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc.

The benefits of a model of interval comprehensive assessments (MICA) in hereditary cancer Syndromes: Hereditary diffuse gastric cancer (HDGC) as an example

A high percentage of individuals at risk for hereditary cancer syndromes are unaware of their risk. This is especially detrimental in syndromes such as hereditary diffuse gastric cancer due to a CDH1 germline mutation, for which lifesaving prevention is possible. Surveillance for diffuse gastric cancer in the syndrome is limited, hence the recommendation for prophylactic total gastrectomy for mutation carriers. Genetic counseling and testing is crucial in suspected families but initial contact could be limited, leading to the importance of an interval comprehensive review every 5–8 years to identify and screen additional high-risk individuals.Our contact with a hereditary diffuse gastric cancer family in Jordan in 2011 led to a number of family members receiving education and genetic counseling. Our model of interval comprehensive assessment (MICA) was constructed and implemented by conducting family information service, video call and emails to the high-risk individuals 7 years after initial contact. Using an updated family pedigree we reached out to an additional thirteen high-risk members in six different countries and provided them with genetic education, counseling, and testing. Six members agreed to CDH1 testing (46%). Four tested positive (66%) and one member (25%) underwent prophylactic total gastrectomy.

Screening of pathogenic genes in a Chinese familial dilated cardiomyopathy pedigree from Inner Mongolia

Objective: Screen the pathogenic genes of a pedigree with clinical manifestation of familial dilated cardiomyopathy in Inner Mongolia. Methods: A total of 3 patients with dilated cardiomyopathy and 20 family members from the same family were examined in Ordos Central Hospital in Inner Mongolia from October, 2003 to August, 2017. Data on medical history, physical examinations, electrocardiograms, and echocardiography were obtained. 5 ml peripheral blood was sampled for per person. Chip Capture Sequencing technology was used to capture all the exons and splice sites of the genes that associated with hereditary cardiomyopathy and hereditary arrhythmia. The mutations in these genes were detected by high-throughput sequencing. All suspected pathogenic loci identified by high-throughput sequencing were verified by Sanger sequencing used for mutation detection. One hundred and fifty gender, age and race matched healthy people were included as the control group. Results: Pathogenic gene variations were detected in 3 symptomatic family members and 1 carrier from the pedigree. Five pathogenic gene variations were identified in the proband (Ⅱ1), a pSer236Gly and a pArg215Cys variation in the MYBPC3 gene, a pGln90Arg variation in the DSP gene, and pAsn2912Asp and pGlu2910Val variation in the DMD gene. One pathogenic variation was detected in Ⅲ3, which was a pArg215Cys variation in the MYBPC3 gene. Two pathogenic variations were detected in Ⅲ7, a pSer236Gly variation in the MYBPC3 gene and a pGln90Arg variation in the DSP gene. Two pathogenic variations were detected in the Ⅳ7, a pSer236Gly variation in the MYBPC3 gene and a pGln90Arg variation in the DSP gene. No gene variation loci were detected in the other family members and the control group. Conclusion: MYBPC3 gene, DSP gene and DMD gene variations are present in the familial dilated cardiomyopathy pedigree from Inner Mongolia, and these variations may be related with familial dilated cardiomyopathy.

Identification of new Wilms tumour predisposition genes: an exome sequencing study

SummaryBackgroundWilms tumour is the most common childhood renal cancer and is genetically heterogeneous. While several Wilms tumour predisposition genes have been identified, there is strong evidence that further predisposition genes are likely to exist. Our study aim was to identify new predisposition genes for Wilms tumour.MethodsIn this exome sequencing study, we analysed lymphocyte DNA from 890 individuals with Wilms tumour, including 91 affected individuals from 49 familial Wilms tumour pedigrees. We used the protein-truncating variant prioritisation method to prioritise potential disease-associated genes for further assessment. We evaluated new predisposition genes in exome sequencing data that we generated in 334 individuals with 27 other childhood cancers and in exome data from The Cancer Genome Atlas obtained from 7632 individuals with 28 adult cancers.FindingsWe identified constitutional cancer-predisposing mutations in 33 individuals with childhood cancer. The three identified genes with the strongest signal in the protein-truncating variant prioritisation analyses were TRIM28, FBXW7, and NYNRIN. 21 of 33 individuals had a mutation in TRIM28; there was a strong parent-of-origin effect, with all ten inherited mutations being maternally transmitted (p=0·00098). We also found a strong association with the rare epithelial subtype of Wilms tumour, with 14 of 16 tumours being epithelial or epithelial predominant. There were no TRIM28 mutations in individuals with other childhood or adult cancers. We identified truncating FBXW7 mutations in four individuals with Wilms tumour and a de-novo non-synonymous FBXW7 mutation in a child with a rhabdoid tumour. Biallelic truncating mutations in NYNRIN were identified in three individuals with Wilms tumour, which is highly unlikely to have occurred by chance (p<0·0001). Finally, we identified two de-novo KDM3B mutations, supporting the role of KDM3B as a childhood cancer predisposition gene.InterpretationThe four new Wilms tumour predisposition genes identified—TRIM28, FBXW7, NYNRIN, and KDM3B—are involved in diverse biological processes and, together with the other 17 known Wilms tumour predisposition genes, account for about 10% of Wilms tumour cases. The overlap between these 21 constitutionally mutated predisposition genes and 20 genes somatically mutated in Wilms tumour is limited, consisting of only four genes. We recommend that all individuals with Wilms tumour should be offered genetic testing and particularly, those with epithelial Wilms tumour should be offered TRIM28 genetic testing. Only a third of the familial Wilms tumour clusters we analysed were attributable to known genes, indicating that further Wilms tumour predisposition factors await discovery.FundingWellcome Trust.

Association between family history, mutation locations, and prevalence of BRCA1 or 2 mutations in ovarian cancer patients.

We investigated the prevalence of germline BRCA mutations in a population‐based cohort of Austrian women diagnosed with ovarian cancer and its association with family history of cancer. We prospectively collected family pedigrees of 443 Austrian ovarian cancer patients who had been tested for the presence of a germline BRCA or 2 mutations and correlated the familial breast and ovarian cancer burden with the prevalence of BRCA mutations and disease onset. The probability of carrying a gBRCA mutation in patients without family history of cancer is 14% (95% CI 9%‐22%), as opposed to 45% (95% CI 31%‐59%) of patients with at least one family member with ovarian cancer, and 47% (95% CI 40%‐54%) if other relatives have developed breast cancer. If both breast and ovarian cancer are diagnosed in the family, the probability of carrying a germline BRCA1 or 2 mutations is 60% (95% CI 50%‐68%). germline BRCA1 or mutations in families with ovarian cancer only are commonly located in the Ovarian Cancer Cluster Regions when compared to families with both breast and ovarian cancer (P = 0.001, and P = 0.020, respectively). While gBRCA mutation carriers with ovarian cancer do not have a significantly different age at onset than patients with a family history of cancer, gBRCA1 carriers in general have an earlier onset than gBRCA2 carriers (P = 0.002) and patients without a mutation (P = 0.006). The rate of germline BRCA1 or 2 mutations in ovarian cancer patients without a family history or breast or ovarian cancer is low. However, in women with additional family members affected, the prevalence is considerably higher than previously reported.

Prevalence of pancreaticobiliary cancer in Irish families with BRCA1 and BRCA2 mutations.

210 Background: Germline mutations in BRCA1 and BRCA2 genes are associated with pancreatic ductal adenocarcinoma (PDAC), and more recently associated with increased risk of biliary tract cancers (BTC). This study assessed the prevalence, age and gender distribution of PDAC/BTC in BRCA1/2 positive families; compared to those of the Irish population. Methods: A review of all families referred to a national genetics clinic from 09/11/1997-01/06/2018 was performed following institutional ethics board approval. Demographics including age, sex and BRCA mutation status was collected in each case of PDAC/BTC. The BOADICEA algorithm was used to estimate the probability that an untested relative of a known BRCA1/2 mutation carrier with PDAC was a carrier. Results: 3252 distinct family pedigrees were reviewed, of which 1193 contained a proband who underwent testing for BRCA1/2 based on Manchester score ≥ 15. Among 128 BRCA2 positive families, 27 (21%) contained a 1st/2nd or 3rd degree relative with PDAC, of 116 BRCA1 positive families, 11 (9%) contained a 1st/ 2nd or 3rd degree relative with PDAC (male: female (m:f) = 1:0.9). Of these 38 families, 25 pts with PDAC had ≥ 50% likelihood of being a mutation carrier by BODICEA analysis. This cohort had a median age at diagnosis of 55 (33-75), with a mean (55) significantly lower than that of 8364 unselected patients with PDAC identified through the National Cancer Registry Ireland (71, p &lt; 0.0001). Six BRCA2 positive (5%) and 2 BRCA1 positive pedigrees (2%) contained an individual with BTC; median age at diagnosis was 65 (33-99, m:f = 1:7). Additional pedigrees with Lynch Syndrome (n = 3), FAP (n = 1) and ATM (n = 2) and PDAC were identified. Conclusions: PDAC and BTC are prevalent in Irish families with a BRCA1/2 mutation and are associated with early onset malignancy. This consolidates evidence of PDAC and BTC as BRCA- associated cancers in the Irish population and supports current guidelines recommending universal germline testing for PDAC patients. [Table: see text]

A germline HLTF mutation in familial MDS induces DNA damage accumulation through impaired PCNA polyubiquitination

Although several causal genes of familial myelodysplastic syndromes (MDS) have been identified, the genetic landscape and the molecular pathogenesis are not totally understood. To explore novel driver genes and their pathogenetic significance, we performed whole-exome sequence analysis of four individuals from a familial MDS pedigree and 10 candidate single-nucleotide variants (C9orf43, CYP7B1, EFHB, ENTPD7, FAM160B2, HELZ2, HLTF, INPP5J, ITPKB, and RYK) were identified. Knockdown screening revealed that Hltf downregulation enhanced colony-forming capacity of primary murine bone marrow (BM) stem/progenitor cells. γH2AX immunofluorescent staining assay revealed increased DNA damage in a human acute myeloid leukemia (AML) cell line ectopically expressing HLTF E259K, which was not observed in cells expressing wild-type HLTF. Silencing of HLTF in human AML cells also led to DNA damage, indicating that HLTF E259K is a loss-of-function mutation. Molecularly, we found that an E259K mutation reduced the binding capacity of HLTF with ubiquitin-conjugating enzymes, methanesulfonate sensitive 2 and ubiquitin-conjugating enzyme E2N, resulting in impaired polyubiquitination of proliferating cell nuclear antigen (PCNA) in HLTF E259K-transduced cells. In summary, our results indicate that a familial MDS-associated HLTF E259K germline mutation induces accumulation of DNA double-strand breaks, possibly through impaired PCNA polyubiquitination.

The association between non-breast and ovary cancers and BRCA mutation in first- and second-degree relatives of high-risk breast cancer patients: a large-scale study of Koreans

BackgroundAs a large-scale study of Koreans, we evaluated the association between BRCA mutation and the prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients.MethodsWe organized familial pedigrees of 2555 patients with breast cancer who underwent genetic screening for BRCA1/2 in Samsung Medical Center between January 2002 and May 2018. Families with a member that had a history of cancer other than of the breast or ovary were regarded positive for other primary cancer.ResultsThe median age of the population was 40 years (range, 19 to 82 years). BRCA mutation was detected in 377 (14.8%) of the patients. The BRCA-positive group had a higher frequency of family history of breast or ovarian cancer (p < 0.001), bilateral breast cancer (p = 0.021), and the male gender (p = 0.038). There were 103 (27.3%) patients who had multiple risk factors in the BRCA-positive group, while there were 165 (7.6%) patients who had multiple risk factors in the BRCA-negative group (p < 0.001). BRCA mutation was detected in 215 (11.7%) of the 1841 families without history of other primary cancers. Among the 714 families with histories of other primary cancers, 162 (22.7%) had BRCA mutation, and this was significantly more frequent (p < 0.001) than in those without a history. The occurrence of other primary cancers in families of high-risk patients was associated with a younger age at diagnosis (p = 0.044), bilateral breast cancer (p = 0.006), and BRCA mutations (p < 0.001). The most common site for the occurrence of another type of primary cancer was the stomach. In the BRCA-positive group, the proportional incidences of stomach, pancreas, colorectal, lung, and uterine cancer were 13.8, 4.0, 7.7, 8.8, and 5.0%, respectively; these were all relatively higher than those in the BRCA-negative group.ConclusionsWe confirmed that BRCA mutation was associated with having multiple risk factors and an increased prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients. Due to the possibility of inherited cancer risk, genetic counseling with options for risk assessment and management should be provided to both patients and families of BRCA mutation carriers.

A Not So Benign Family Pedigree With Hereditary Chorea: A Broader Phenotypic Expression or Additional Picture?

NKX2-1 mutations have been usually associated with a non-progressive neurological disease. Recent reports revealed a vast variability regarding its clinical expressivity. Aim of this work was widening the Benign Hereditary Chorea neurological, cognitive and behavioral phenotype through the description of a child and her family pedigree. Molecular analysis focused on NKX2-1 gene revealed a novel frameshift mutation in the three-generation members described. Cognitive scales detected a relevant developmental delay, and the clinical observation and Autism Diagnostic Observation Schedule -2 administration allowed the diagnosis of autism spectrum disorder in the proband. Microarray testing, further executed to exclude a double hit contextually provoking the complex neurodevelopmental disorder, revealed the 22q11.2 Duplication Syndrome. This paper may contribute to enlarge Benign Hereditary Chorea variable expressivity and, together with other studies reported in the literature, underlines the need to reconsider the term “benign,” verifying the opportunity of more a complex diagnosis.

SEMIPARAMETRIC TRANSFORMATION MODELS WITH MULTILEVEL RANDOM EFFECTS FOR CORRELATED DISEASE ONSET IN FAMILIES.

Large cohort studies are commonly launched to study risk of genetic variants or other risk factors on age at onset (AAO) of a chronic disorder. In these studies, family history data including AAO of disease in family members are collected to provide additional information and can be used to improve efficiency. Statistical analysis of these data is challenging due to missing genotypes in family members and the heterogeneous dependence attributed to both shared genetic back-ground and shared environmental factors (e.g., life style). In this paper, we propose a class of semiparametric transformation models with multilevel random effects to tackle these challenges. The proposed models include both proportional hazards model and proportional odds model as special cases. The multilevel random effects contain individual-specific random effects including kinship correlation structure dependent on the family pedigree, and a shared random effect to account for unobserved environment exposure. We use nonparametric maximum likelihood approach for inference and propose an expectation-maximization algorithm for computation in the presence of missing genotypes among family members. The obtained estimators are shown to be consistent, asymptotically normal, and semiparametrically efficient. Simulation studies demonstrate that the proposed method performs well with finite sample sizes. Finally, the proposed method is applied to study genetic risks in an Alzheimer's disease study.

Patterns of Dystrophin Gene Deletion/Duplication in a Sample of Saudi Patients with Duchenne Muscular Dystrophy

Introduction: Duchenne muscular dystrophy (DMD) is caused by the lack of functional dystrophin molecules, either due to nonsense mutations (premature stop codons) or by large rearrangements (deletions or duplications) that disturb the reading frame and in consequence abolish the production of dystrophin in muscles. Methods: Twenty patients with muscular dystrophy diagnosed by clinical history, family pedigree, CK total and histopathology of muscle biopsy is subjected to screening for all 79 exons of dystrophin gene for deletions and duplications. Results and Discussion: Deletion was detected in 80% of patients, while 15% showed duplication, one patient shows nucleotide substitution (c.10033C>T) in exon 69. Most common deletion found between exon 44 and 52. Conclusion: Our study detected high incidence of gene deletion compared to other studies, the most common deletion is multi exon deletion in the major hot spot of the gene (exon 44-52), also we detected lower incidence of duplication with higher percentage of duplication found distally.

Familial Dilated Cardiomyopathy – Enhancing Detection Using Systematic Screening

Background: Dilated cardiomyopathy (DCM) is the leading indication for heart transplantation in New Zealand (NZ). The familial subtype (FDCM) is aggressive, presents early, and is implicated in up to 50% of idiopathic DCM (IDCM). Diagnosis requires an affected individual having ≥2 affected close relatives. Adequate family pedigree analysis is diagnostically essential, and screening relatives is imperative as pre-symptomatic therapy improves outcomes. We utilised a validated family history survey to screen our NZ heart transplant population for FDCM more systematically. Methods: Medical records of living heart transplant patients with IDCM or FDCM diagnoses (77/339 patients) were reviewed. Patients were provided our survey via post/email and at clinic visits. We evaluated our 12 question clinical survey's efficacy in obtaining a complete three-generation family history and compared that to information documented in the medical records. Results: Fifty-one (66%) surveys were returned. Complete family history was obtained in 47/51 (92.2%), compared with 10/51 (19.6%) specifically documented in medical records. Responders identified 16 relatives who were also referred for heart transplantation, or who died ≤50 years with cardiomyopathy. The tool diagnosed FDCM in 25/51 (49.0%, with a further 3 possible FDCM), already yielding 6 additional patients not previously diagnosed. The mean age at first presentation of FDCM was 37 years (23 were male, 2 female), compared with 43 years in the IDCM group. Conclusion: Utilising a formal family screening tool improves pedigree analysis ensuring more effective detection of FDCM, which is prevalent in the NZ transplant cohort. Formalised systematic screening has great potential to improve outcomes.

Structural and Contextual Patterns in Family Health History Knowledge among African American Adults: A Mixed-Methods Social Network Analysis Study*

Abstract Background: Family health history is a strong risk factor for many chronic diseases. Ethnic minorities have been found to have a low awareness of their family health history (FHH), which may pose a contributing factor to health disparities. Purpose: The purpose of this mixed-methods social network analysis study was to identify structural and contextual patterns in African American adults’ FHH knowledge based on interpersonal communication exchanges with their family members. Methods: African American adults completed individually administered family network interviews. Participants’ 3-generation family pedigree served as a visual aid to guide their interview. Our primary outcome of interest for this analysis was whether a family member was reported as someone who talks to the participant about their own (i.e., the family member’s) health, which we refer to as a “personal health informant.” To contextualize quantitative findings, participants were asked to describe how they learned about the health history of the relatives they identified during their interview. Results: Participants (n=37) reported an average family network size of 29.4 relatives (SD = 15.5; Range = 10-67). Each participant, on average, named 17% of their familial network as personal health informants. Multivariate regression results showed that participants were more likely to name an alter as a personal health informant if the alter was female (OR = 2.14, p = 0.0519), from the maternal side of the participant’s family (OR = 1.12, p = 0.0006), had one or more chronic health conditions (OR = 2.41, p = 0.0041), was someone who has discussions with the participant about the participant’s health (OR = 16.28, p &lt; 0.0001), was a source of family health information (OR = 3.46, p = 0.0072), and was someone whose health the participant helps to monitor or track (OR = 5.93, p = 0.0002). Complementary qualitative findings indicate that FHH knowledge is facilitated by open, direct communication among relatives. Personal health informants were described as disclosing information for the purposes of informing others for preventive purposes and for gaining social support. Participants also learned about FHH via other methods, including direct observation, during caretaking, and following a relative’s death. Conclusions: Communication and disclosure practices is an important determinant of African Americans’ FHH knowledge. More culturally and contextually meaningful public health efforts are needed to promote family health history sharing, especially regarding paternal family health history, siblings, and extended relatives.

The clinical application of gene diagnosis and genetic counseling on hereditary hearing loss

Objective:To summarize the clinic procedure and experience about gene diagnosis and genetic counseling on hereditary hearing loss, and explore the strategy and principle about gene diagnosis and genetic counseling on hereditary hearing loss.Method:A retrospective analysis was used on the clinical data of 151 cases who aim at genetic counseling. The all cases were divided into 5 groups according to the purpose of genetic counseling, such as the occurrence risk of hearing loss, the etiological analysis, the choice of the intervention way, the examination guidance, the prevention of hearing loss and the usage requirement of Aminogly cosides drugs. The counseling procedure includes the investigation of the etiology and family history, drawing the family pedigree, general physical examination, auditory examination and genetic analysis. Sanger sequencing analysis and/or Targeted nextgeneration sequencing was utilized to detect the deaf-gene mutations. At last, the genetic counseling, fertility guidance and prenatal diagnosis will be made on the basis of the results of gene detection. Result:There are 33 newborns who did not pass the deafgene screening, 9 of them could be diagnosed definitely as hereditary hearing loss, and the other 24 were the carriers of deafgene mutation. Eighty of 104 deaf patients were diagnosed definitely as hereditary hearing loss and the related gene mutation was found. Six objects in the 10 patients with auditory neuropathy are diagnosed as OTOF or SLC17A8 gene mutations before cochlear implantation. Three of 7 reproductive age objects who had family history were recessive deaf-gene carriers, 2 of them carried the same target gene with the mate who receive our fertility guidance and prenatal diagnose. The other 1 object carried the dominant genetic mutation(incomplete dominant heredity). There were 4 pregnant women who did not pass the deaf-gene screening, 1 of them carry the same target gene with the mate. The populations who want to use Aminoglycosides drugs were not diagnosed as carrying any related mitochondrial gene mutation. We carried out the genetic counseling according to the results of gens detection and clinical phenotype.Conclusion:Genetic counseling is based on the different purpose. The analysis of gene diagnosis should be considered to combine with the clinical phenotype. The principle of choosing the objects to make a gene diagnosis includes: ①the all deaf-genes sequencing was applied for the deaf patients. ② the screening target gene sequencing was used for the newborns who did not pass the deaf-gene screening and the mate whose pregnant wife did not pass the deafgene screening. ③the specific target gene sequencing could be used for the patients who has a clear family history or specific phenotype.

A whole genome approach for discovering the genetic basis of blood group antigens: independent confirmation for P1 and Xga.

Although P1 and Xga are known to be associated with the A4GALT and XG genes, respectively, the genetic basis of antigen expression has been elusive. Recent reports link both P1 and Xga expression with nucleotide changes in the promotor regions and with antigen-negative phenotypes due to disruption of transcription factor binding. Whole genome sequencing was performed on 113 individuals as part of the MedSeq Project with serologic RBC antigen typing for P1 (n = 77) and Xga (n = 15). Genomic data were analyzed by two approaches, nucleotide frequency correlation and serologic correlation, to find A4GALT and XG changes associated with P1 and Xga expression. For P1, the frequency approach identified 29 possible associated nucleotide changes, and the serologic approach revealed four among them correlating with the P1+/P1- phenotype: chr22:43,115,523_43,115,520AAAG/delAAAG (rs66781836); chr 22:43,114,551C/T (rs8138197); chr22:43,114,020 T/G (rs2143918); and chr22:43,113,793G/T (rs5751348). For Xga , the frequency approach identified 82 possible associated nucleotide changes, and among these the serologic approach revealed one correlating with the Xg(a+)/Xg(a-) phenotype: chrX:2,666,384G/C (rs311103). A bioinformatics analysis pipeline was created to identify genetic changes responsible for RBC antigen expression. This study, in progress before the recently published reports, independently confirms the basis for P1 and Xga . Although this enabled molecular typing of these antigens, the Y chromosome PAR1 region interfered with Xga typing in males. This approach could be used to identify and confirm the genetic basis of antigens, potentially replacing the historical approach using family pedigrees as genomic sequencing becomes commonplace.

Common fragile site instability in normal cells: Lessons and perspectives.

Mechanisms and events related to common fragile site (CFS) instability are well known in cancer cells. Here, we argue that normal cells remain an important experimental model to address questions related to CFS instability in the absence of alterations in cell cycle and DNA damage repair pathways, which are common features acquired in cancer. Furthermore, a major gap of knowledge concerns the stability of CFSs during gametogenesis. CFS instability in meiotic or postmeiotic stages of the germ cell line could generate chromosome deletions or large rearrangements. This in turn can lead to the functional loss of the several CFS-associated genes with tumor suppressor function. Our hypothesis is that such mutations can potentially result in genetic predisposition to develop cancer. Indirect evidence for CFS instability in human germ cells has been provided by genomic investigations in family pedigrees associated with genetic disease. The issue of CFS instability in the germ cell line should represent one of the future efforts, and may take advantage of the existence of sequence and functional conservation of CFSs between rodents and humans.

A game of hide and seq: Identification of parallel Y-STR evolution in deep-rooting pedigrees.

Short tandem repeats on the Y-chromosome (Y-STRs) are common DNA polymorphisms useful for genetic genealogy, population and evolutionary genetics, human genetics, pathology and forensic sciences. It is important to identify all Y-STR variants and to have knowledge of Y-STR mutation rates in order to correctly estimate the time to the most recent common ancestor (tMRCA) between paternally related individuals. When capillary electrophoresis (CE) is performed to analyze genealogical pairs, Y-STR sequence variations remain hidden when the number of repeats is identical. These hidden variations could be due to parallel Y-STR changes or modifications (PM) that occur independently in different lineages leading to alleles with identical number of repeats. In this study, we detect for the first time twelve PM by analyzing 133 males (960 meiosis) in extended deep-rooting family pedigrees on 42 Y-STRs. These PM were observed in nine Y-STR loci with mutation rates of at least 5.94 × 10-3 per generation. Sequencing analysis made it possible to distinguish insertions/deletions in different repeat regions revealing the presence of two unique changes in three PM on rapidly mutating and complex Y-STRs DYS724-ab and DYS518. Sequencing unraveled more information concerning the identity of alleles, and increased allelic discrimination possibilities which is of great importance in population genetics and forensic analysis. Limiting the analysis to CE could lead to wrong ancestral allele assumptions, to false negative interpretations and to tMRCA underestimations. These observations highlight the importance and added value of sequencing analysis and suggest a shift in genotyping methods from CE to next generation sequencing.

TDRKH is a candidate gene for an autosomal dominant distal hereditary motor neuropathy

Distal hereditary motor neuropathies (dHMNs) comprise a group of clinically and genetically heterogeneous inherited lower motor neuron syndromes mainly characterized by a distal-predominant pattern of progressive muscle atrophy, weakness and hyporeflexia, without sensory dysfunction. Although at least 21 causative genes for dHMN have been reported, mutational scanning of these genes often fails to identify the causative variants in dHMN cohorts, suggesting that additional causative genes remain to be identified. We studied a four-generation pedigree of a Japanese family with autosomal dominant dHMN to provide insight into the pathogenetic basis of the disease. Neurological examinations were performed on all six family members enrolled in this study. Whole-exome sequencing (WES) was used to identify the causative gene for dHMN. The clinical features of the patients included muscle weakness with distal extensor dominancy in the lower extremities, accompanied by facial and neck flexor muscle impairment, no sensory involvement, and areflexia. Nerve conduction studies demonstrated axonal changes mainly in the peroneal nerve. WES combined with rigorous filtering revealed three missense variants (NM_001083964: c.851G > A [p.Arg284His] in TDRKH, NM_002858: c.1654G > T [p.Gly552Cys] in ABCD3, NM_001005164: c.898A > T [p.Ile300Phe], in OR52E2). The variant in TDRKH is located in a conserved region of the tudor domain which is also present in the survival of motor neuron (SMN) protein, encoded by the SMN1 gene. Therefore, we concluded the variant in TDRKH is likely to be responsible for dHMN in our pedigree.

A Heterozygous Mutation of G-Protein-Coupled Receptor 25 in a Family with Inherited Thrombocytopenia and Thrombosis

BackgroundInherited thrombocytopenia is associated with bleeding tendency and no association with thrombotic tendency has been reported. We found a Japanese family with autosomal dominant form of thrombocytopenia associated with arterial and venous thrombosis.AimsTo identify a causative gene for hereditary thrombocytopenia with thrombosis.MethodsA propositus was a 42-year-old Japanese woman with thrombocytopenia and deep vein thrombosis (DVT). She had normal activities of antithrombin, protein C, and protein S, and negative results for lupus anticoagulant and anti-cardiolipin antibodies. She has suffered from thrombocytopenia (20 - 50 x 109/L) for at least 20 years. Six members among her family pedigree had thrombocytopenia, and also suffered from thrombosis including mesenteric artery thrombosis, young-onset myocardial infarction, femoral artery thrombosis, repeated cerebral infarction, DVT, and pulmonary embolism. Importantly, the family members with these thrombotic disorders had exclusively thrombocytopenia. Whole exome sequencing was performed with venous blood from the 6 affected and 6 non-affected family members to identify a causative gene for thrombocytopenia.ResultsWe identified a heterozygous change (c.764G>T:p.G255V) in GPR25 gene, an uncharacterized G protein-coupled receptor. The mutation was completely linked with thrombocytopenia. The mutated residue was located at the transmembrane domain of GPR25. We generated anti-GPR25 monoclonal antibodies and confirmed that GPR25 was expressed on the platelet surface. The patient's platelets showed the same level of PAC1 (a monoclonal antibody recognizing the active conformation of integrin αIIbβ3) binding and P-selectin expression as platelets from healthy subjects. However, ADP-induced aggregation of patient's washed platelets was enhanced as compared with normal washed platelets. Moreover, the patient's platelets had an increase in thrombin + collagen-induced and A23187-induced Annexin V binding compared with platelets from healthy subjects.ConclusionWe identified a novel gene mutation responsible for inherited thrombocytopenia and thrombosis that may induce platelet hyper-reactivity. DisclosuresNo relevant conflicts of interest to declare.