scholarly journals Genetic Heterogeneity in GJB2, COL4A3, ATP6V1B1 and EDNRB Variants Detected Among Hearing Impaired Families in Morocco

Author(s):  
Imane Aitraise ◽  
Ghita Amalou ◽  
Hicham Charoute ◽  
Mostafa Kandil ◽  
Hassan Rouba ◽  
...  

Abstract Deafness has a very variable disease. It may occur as a result of external auditory canal involvement or a deficiency in the sound conduction mechanism (transmission deafness) or impairment of the cochlear, cochlear nerve or central auditory perception. Genetics is the most common cause, as approximately 70% of hearing disorders are of hereditary origin. 1/3 of hereditary deafness is syndromic (associated with other symptoms) and 2/3 are non-syndromic (isolated deafness). At this date, 173 loci of deafness gene have been reported in the literature (69 DFNA, 94 DFNB, 6 X-linked DFN, 2 DFNM, 1 DFNY and 1 AUNA1). For syndromic deafness, approximately 400 syndromes associated with hearing disorders are already described. Thus, the determination of causal mutations is a valuable aid for accurate and early diagnosis. This makes it possible to better guide the management since forms of deafness respond better to the cochlear implant than others. The correct diagnosis also gives an idea of ​​the evolutionary profile of deafness and whether it is a syndromic deafness requiring special surveillance. In this study, we have examined the genetic causes of sensorineural hearing loss in Moroccan patients through whole exome sequencing (WES) to identify candidate genes for six severely deaf Moroccan families. The results revealed four genetic variants in the genes GJB2, COL4A3, ATP6V1B1 and EDNRB, which are therefore common causes of syndromic and non-syndromic deafness.

2019 ◽  
Author(s):  
Shahab Noorian ◽  
Farzaneh Rohani ◽  
Shahram Savad ◽  
Kourosh Kabir ◽  
Nami Mohammadian Khonsari ◽  
...  

Abstract Introduction: one of the most common causes of referrals to paediatricians is short stature (ISS), some pathogenic mutations may present exactly similar to non-pathogenic causes, our goal is to identify and treat these patients labelled ISS with these mutations and hopefully treat them correctly. Materials and Methods: We assessed All children under the age of fifteen years labelled as ISS. Fourteen of them were confirmed to be ISS and thus were allowed in our study. Afterwards, we pooled their blood specimens and ordered a whole-exome sequencing (WES) test. Results: five patient had normal WES results. Four patients had rare motions that were not studied in the previous literature but due to the functions of the genes, and our patients’ phenotypes it is highly possible that these mutations caused our patients’ short stature. Four patients had known genetic mutations causing short stature. One patient had a mutation with no effect on height. With the help of WES, some rare mutations were found, with the patients’ phenotype and evaluation we identified their function, we diagnosed some other patients’ rare genetic disorders and assessed the possible effect of their mutation on their height and phenotype we aimed to determine how many children labelled as ISS are correctly diagnosed. By WES most of our patient achieved the correct diagnosis which would be impossible to diagnose without WES; thus the reason for their short stature was identified, with the correct diagnosis now we can aim for the proper treatment.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dongdong Tang ◽  
Yanwei Sha ◽  
Yang Gao ◽  
Jingjing Zhang ◽  
Huiru Cheng ◽  
...  

Abstract Background Asthenozoospermia is one of the most common causes of male infertility, and its genetic etiology is poorly understood. DNAH9 is a core component of outer dynein arms in cilia and flagellum. It was reported that variants of DNAH9 (OMIM: 603330) might cause primary ciliary dyskinesia (PCD). However, variants in DNAH9 lead to nonsyndromic severe asthenozoospermia have yet to be reported. Methods Whole exome sequencing (WES) was performed for two individuals with nonsyndromic severe asthenozoospermia from two non-consanguineous families, and Sanger sequencing was performed to verify the identified variants and parental origins. Sperm routine analysis, sperm vitality rate and sperm morphology analysis were performed according the WHO guidelines 2010 (5th edition). Transmission electron microscopy (TEM, TECNAI-10, 80 kV, Philips, Holland) was used to observe ultrastructures of sperm tail. Quantitative realtime-PCR and immunofluorescence staining were performed to detect the expression of DNAH9-mRNA and location of DNAH9-protein. Furthermore, assisted reproductive procedures were applied. Results By WES and Sanger sequencing, compound heterozygous DNAH9 (NM_001372.4) variants were identified in the two individuals with nonsyndromic severe asthenozoospermia (F1 II-1: c.302dupT, p.Leu101fs*47 / c.6956A > G, p.Asp2319Gly; F2 II-1: c.6294 T > A, p.Phe2098Leu / c.10571 T > A, p.Leu3524Gln). Progressive rates less than 1% with normal sperm morphology rates and normal vitality rates were found in both of the two subjects. No respiratory phenotypes, situs inversus or other malformations were found by detailed medical history, physical examination and lung CT scans etc. Moreover, the expression of DNAH9-mRNA was significantly decreased in sperm from F1 II-1. And expression of DNAH9 is lower in sperm tail by immunofluorescence staining in F1 II-1 compared with normal control. Notably, by intracytoplasmic sperm injection (ICSI), F1 II-1 and his partner successfully achieved clinical pregnancy. Conclusions We identified DNAH9 as a novel pathogenic gene for nonsyndromic severe asthenospermia, and ICSI can contribute to favorable pregnancy outcomes for these patients.


2020 ◽  
Author(s):  
Rosella Scrima ◽  
Sabino Fugetto ◽  
Nazzareno Capitanio ◽  
Domenico L. Gatti

AbstractAbnormal hemoglobins can have major consequences for tissue delivery of oxygen. Correct diagnosis of hemoglobinopathies with altered oxygen affinity requires a determination of hemoglobin oxygen dissociation curve (ODC), which relates the hemoglobin oxygen saturation to the partial pressure of oxygen in the blood. Determination of the ODC of human hemoglobin is typically carried out under conditions in which hemoglobin is in equilibrium with O2 at each partial pressure. However, in the human body due to the fast transit of RBCs through tissues hemoglobin oxygen exchanges occur under non-equilibrium conditions. We describe the determination of non-equilibrium ODC, and show that under these conditions Hb cooperativity has two apparent components in the Adair, Perutz, and MWC models of Hb. The first component, which we call sequential cooperativity, accounts for ∼70% of Hb cooperativity, and emerges from the constraint of sequential binding that is shared by the three models. The second component, which we call conformational cooperativity, accounts for ∼30% of Hb cooperativity, and is due either to a conformational equilibrium between low affinity and high affinity tetramers (as in the MWC model), or to a conformational change from low to high affinity once two of the tetramer sites are occupied (Perutz model).


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 33-34
Author(s):  
Marwan Elbagoury ◽  
Ohoud F. Kashari

Rationale Around the globe, it is now understood that individuals with Rare genetic Diseases routinely face limitations to getting access to diagnosis. Plans have been created to improve the requirements of the patient's communities, including access to multidisciplinary care, and proposing new corrections or amendments to existing strategies. In the gulf region, numerous proposals have been established to tackle the diagnosis and management Rare genetic Diseases. Introduction and Background Rare genetic diseases are characterized as life-long, serious conditions that debilitate or compromise life. Almost 80% of Rare genetic diseases are diagnosed during the childhood. Absence of access to these assets affect patients and their families living with complex needs that may incorporate day in and day out observing, continuous serious physical and formative medicines, remaining in the training framework, and now and then costly strength meds1. The underlying etiology may stay obscure for many patients with rare genetic diseases despite multiple investigations. patients may be assigned an incorrect diagnosis and be referred to several specialties until a correct diagnosis can be made. A correct diagnosis of rare genetic diseases may impact not only the patient's care but may have further implications for management and/or counselling of family members as well2. Also, Early diagnosis leading to early treatment to prevent long-term damage. Global Landscape3 Rarity of diseases is most commonly defined based on prevalence and incidence within a jurisdiction, or in some cases by a combination of factors based on severity and the existence or feasibility of alternative therapeutic options. Globally, the following areas of focus aimed at improving the delivery of health care for the rare disease population: - Improve access to early diagnosis, timely intervention, coordinated care for rare genetic disease patients and developing referral pathways for rare genetic disease patients to facilitate efficient care deliver - Provide educational resources and knowledge exchange opportunities to health professionals to allow them to better identify, manage and treat rare disea - support integrated peer networks, patient organizations to ensure that rare disease patients, their family/caregivers and support them to make informed decisions about their condition. The importance of having working groups for Rare genetic Diseases in Gulf region 4 - Encourage improved coordination of care and access to particular information for rare genetic diseaseses. - Create a complete system services suppliers over Gulf states. Assets and Gaps analysis 1- Early Detection and Diagnostics 5 There are resources that assist the diagnostic capacity and early detection for rare genetic diseases. · Whole Exome sequencing are used mainly for research purposes, despite the fact that their use will reduced diagnostic odyssey. · Lack of the availability of testing is dependent on budget support in some hospitals. - Timely Access to Evidence-based care 6 - Family doctors may not be well equipped to meet the needs of patients with rare hematological genetic diseases, even after diagnosis. - Poor access supportive services for adult care. - Access to genetic counseling for patients and families outside major academic hospitals7. References 1. Sawyer, S. L. et al. Utility of whole-exome sequencing for those near the end of the diagnostic odyssey: time to address gaps in care. Clin. Genet.89, 275-284 (2016). 2. Undiagnosed Diseases Network Manual of Operations. (2018). 3. Richter, T. et al. Rare Disease Terminology and Definitions-A Systematic Global Review: Report of the ISPOR Rare Disease Special Interest Group. (2015). doi:10.1016/j.jval.2015.05.008 4. International Rare Disease Research Consortium& GUIDELINES Long version. (2013). 5. Clinical Handbook for Sickle Cell Disease Vaso-occlusive Crisis Provincial Council for Maternal and Child Health & Ministry of Health and Long-Term Care. (2017). 6. Therrell, B. L. et al. Current status of newborn screening worldwide: 2015. Seminars in Perinatology39, 171-187 (2015). 7. Stille, C. J. & Antonelli, R. C. Coordination of care for children with special health care needs. Current Opinion in Pediatrics16, 700-705 (2004). Figure Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 57 (7) ◽  
pp. 479-486 ◽  
Author(s):  
Brett Doble ◽  
Deborah Schofield ◽  
Carey-Anne Evans ◽  
Tudor Groza ◽  
John S Mattick ◽  
...  

BackgroundThis study provides an integrated assessment of the economic and social impacts of genomic sequencing for the detection of monogenic disorders resulting in intellectual disability (ID).MethodsMultiple knowledge bases were cross-referenced and analysed to compile a reference list of monogenic disorders associated with ID. Multiple literature searches were used to quantify the health and social costs for the care of people with ID. Health and social expenditures and the current cost of whole-exome sequencing and whole-genome sequencing were quantified in relation to the more common causes of ID and their impact on lifespan.ResultsOn average, individuals with ID incur annual costs in terms of health costs, disability support, lost income and other social costs of US$172 000, accumulating to many millions of dollars over a lifetime.ConclusionThe diagnosis of monogenic disorders through genomic testing provides the opportunity to improve the diagnosis and management, and to reduce the costs of ID through informed reproductive decisions, reductions in unproductive diagnostic tests and increasingly targeted therapies.


Author(s):  
José María García-Aznar ◽  
Noelia Ramírez ◽  
David De Uña ◽  
Elisa Santiago ◽  
Lorenzo Monserrat

AbstractThe diagnosis of rare diseases with multisystem manifestations can constitute a difficult process that delays the determination of the underlying cause. Whole exome sequencing (WES) provides a suitable option to examine multiple target genes associated with several disorders that display common features. In this study, we report the case of a female patient suspected of having Sotos syndrome. Screening for the initially selected genes, considering Sotos syndrome and Sotos-like disorders, did not identify any pathogenic variants that could explain the phenotype. The extended analysis, which considered all genes in the exome associated with features consistent with those shown by the studied patient, revealed a novel frameshift variant in the AMER1 gene, responsible for osteopathia striata with cranial sclerosis. WES analysis and an updated revision of previously reported disease-causing mutations, proved useful to reach an accurate diagnosis and guide further examination to identify critical abnormalities.


Gene Reports ◽  
2020 ◽  
Vol 19 ◽  
pp. 100618
Author(s):  
Ceyda Hayretdag ◽  
Pinar Algedik ◽  
Cumhur Gokhan Ekmekci ◽  
Ozlem Bozdagi Gunal ◽  
Umut Agyuz ◽  
...  

2020 ◽  
Vol 57 (7) ◽  
pp. 445-453 ◽  
Author(s):  
Mingrong Lv ◽  
Wangjie Liu ◽  
Wangfei Chi ◽  
Xiaoqing Ni ◽  
Jiajia Wang ◽  
...  

BackgroundAsthenoteratospermia, one of the most common causes for male infertility, often presents with defective sperm heads and/or flagella. Multiple morphological abnormalities of the sperm flagella (MMAF) is one of the common clinical manifestations of asthenoteratospermia. Variants in several genes including DNAH1, CEP135, CATSPER2 and SUN5 are involved in the genetic pathogenesis of asthenoteratospermia. However, more than half of the asthenoteratospermia cases cannot be explained by the known pathogenic genes.Methods and resultsTwo asthenoteratospermia-affected men with severe MMAF (absent flagella in >90% spermatozoa) from consanguineous families were subjected to whole-exome sequencing. The first proband had a homozygous missense mutation c.188G>A (p.Arg63Gln) of DZIP1 and the second proband had a homozygous stop-gain mutation c.690T>G (p.Tyr230*). Both of the mutations were neither detected in the human population genome data (1000 Genomes Project, Exome Aggregation Consortium) nor in our own data of a cohort of 875 Han Chinese control populations. DZIP1 encodes a DAZ (a protein deleted in azoospermia) interacting protein, which was associated with centrosomes in mammalian cells. Immunofluorescence staining of the centriolar protein Centrin1 indicated that the spermatozoa of the proband presented with abnormal centrosomes, including no concentrated centriolar dot or more than two centriolar dots. HEK293T cells transfected with two DZIP1-mutated constructs showed reduced DZIP1 level or truncated DZIP1. The Dzip1-knockout mice, generated by the CRSIPR-Cas9, revealed consistent phenotypes of severe MMAF.ConclusionOur study strongly suggests that homozygous DZIP1 mutations can induce asthenoteratospermia with severe MMAF. The deficiency of DZIP1 induces sperm centrioles dysfunction and causes the absence of flagella.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Min Chen ◽  
Min Zhang ◽  
Yeqing Qian ◽  
Yanmei Yang ◽  
Yixi Sun ◽  
...  

Abstract Recent advances in Bionano optical mapping (BOM) provide a great insight into the determination of structural variants (SVs), but its utility in identification of clinical likely pathogenic variants needs to be further demonstrated and proved. In a family with two consecutive pregnancies affected with ventriculomegaly, a splicing likely pathogenic variant at the LAMA1 locus (NM_005559: c. 4663 + 1 G > C) inherited from the father was identified in the proband by whole-exome sequencing, and no other pathogenic variant associated with the clinical phenotypes was detected. SV analysis by BOM revealed an ~48 kb duplication at the LAMA1 locus in the maternal sample. Real-time quantitative PCR and Sanger sequencing further confirmed the duplication as c.859-153_4806 + 910dup. Based on these variants, we hypothesize that the fetuses have Poretti-Boltshauser syndrome (PBS) presenting with ventriculomegaly. With the ability to determine single nucleotide variants and SVs, the strategy adopted here might be useful to detect cases missed by current routine screening methods. In addition, our study may broaden the phenotypic spectrum of fetuses with PBS.


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