scholarly journals A Novel Missense Variant of HOXD13 Caused Atypical Synpolydactyly by Impairing the Downstream Gene Expression and Literature Review for Genotype–Phenotype Correlations

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruiji Guo ◽  
Xia Fang ◽  
Hailei Mao ◽  
Bin Sun ◽  
Jiateng Zhou ◽  
...  
Keyword(s):  
Limb Development ◽  
Missense Variant ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Phenotype Correlation ◽  
Mutation Site ◽  
Genotype Phenotype Correlation ◽  
Α Helix ◽  
Severe Degree ◽  
Hands And Feet

Synpolydactyly (SPD) is a hereditary congenital limb malformation with distinct syndactyly designated as SPD1, SPD2, and SPD3. SPD1 is caused by mutations of HOXD13, which is a homeobox transcription factor crucial for limb development. More than 143 SPD patients have been reported to carry HOXD13 mutations, but there is a lack of genotype–phenotype correlation. We report a novel missense mutation of c. 925A > T (p.I309F) in an individual with atypical synpolydactyly inherited from her father with mild clinodactyly and three other different alanine insertion mutations in HOXD13 identified by whole exome sequencing (WES) in 12 Chinese SPD families. Unlike polyalanine extension, which tends to form α-helix and causes protein aggregation in the cytoplasm as shown by molecular simulation and immunofluorescence, the c. 925A > T mutation impairs downstream transcription of EPHA7. We compiled literature findings and analyzed genotype–phenotype features in 173 SPD individuals of 53 families, including 12 newly identified families. Among the HOXD13-related individuals, mutations were distributed in three regions: polyalanine, homeobox, and non-homeobox. Polyalanine extension was the most common variant (45%), followed by missense mutations (32%) mostly in the homeobox compared with the loss-of-function (LOF) variants more likely in non-homeobox. Furthermore, a more severe degree and classic SPD were associated with polyalanine mutations although missense variants were associated with brachydactyly and syndactyly in hands and feet and LOF variants with clinodactyly in hands. Our study broadens the HOXD13 mutation spectrum and reveals the profile of three different variants and their severity of SPD, the genotype–phenotype correlation related to the HOXD13 mutation site provides clinical insight, including for genetic counseling.

scholarly journals MIRAGE syndrome caused by a novel missense variant (p.Ala1479Ser) in the SAMD9 gene

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shinsuke Onuma ◽  
Tamaki Wada ◽  
Ryosuke Araki ◽  
Kazuko Wada ◽  
Kanako Tanase-Nakao ◽  
...  
Keyword(s):  
Japanese Patient ◽  
De Novo ◽  
Missense Variant ◽  
Phenotype Correlation ◽  
Gain Of Function ◽  
Limited Knowledge ◽  
Genotype Phenotype Correlation ◽  
Adrenal Hypoplasia

AbstractMIRAGE syndrome is a recently identified disorder characterized by myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy. It is caused by a gain-of-function variant in the SAMD9 gene, but there is limited knowledge regarding the genotype–phenotype correlation. We herein report a Japanese patient with MIRAGE syndrome carrying a novel de novo heterozygous missense variant in the SAMD9 gene (c.4435 G > T; p.Ala1479Ser).

scholarly journals Mutation analysis of the ATP7B gene and genotype-phenotype correlation in Chinese patients with Wilson disease

2021 ◽  
Author(s):  
Mingming Li ◽  
Jing Ma ◽  
Wenlong Wang ◽  
Xu Yang ◽  
Kaizhong Luo
Keyword(s):  
Wilson Disease ◽  
Large Scale ◽  
Allelic Frequency ◽  
Chinese Patients ◽  
Missense Mutations ◽  
Onset Age ◽  
Phenotype Correlation ◽  
Novel Mutations ◽  
Nonsense Mutations ◽  
Genotype Phenotype Correlation

Abstract AIM To discover the novel ATP7B mutations in 103 southern Chinese patients with Wilson disease (WD), and to determine the spectrum and frequency of mutations in the ATP7B gene and genotype-phenotype correlation in a large-scale sample of Chinese WD patients. Methods One hundred three WD patients from 101 unrelated families in southern China were enrolled in this study. Genomic DNA was extracted from the peripheral blood. Direct sequencing of all 21 exons within ATP7B was performed. Subsequently, an extensive study of the overall spectrum and frequency of ATP7B mutations and genotype-phenotype correlation was performed in all Chinese patients eligible from the literature, combined with the current southern group.Results In 103 patients with WD, we identified 48 different mutations (42 missense mutations, 4 nonsense mutations and 2 frameshifts). Of these, 7 mutations had not been previously reported: 1510_1511insA, 2075T>C (Leu692Pro), 2233C>A (Leu745Met), 3209C>G (Pro1070Arg),3677C>T (Thr1226Ile), 3793G>T (Val1265Leu) and 3824T>C (Leu1275Ser). The 2333G>T (Arg778 Leu) at exon 8, was the most common mutation with an allelic frequency of 18.8%, followed by 2975C>T (Pro992Leu) at exon 13, with an allelic frequency of 13.4%. In the comprehensive study, 233 distinct mutations were identified, including 154 missense mutations, 23 nonsense mutations and 56 frameshifts. Eighty-five variants were identified as novel mutations. The 2333G>T (Arg778 Leu) and 2975C>T (Pro992Leu) were the most common mutations, with allelic frequencies of 28.6% and 13.0%, respectively. Exons 8, 12, 13, 16 and 18 were recognised as hot spot exons. Phenotype-genotype correlation analysis suggested that 2333G>T (Arg778 Leu) was significantly associated with lower levels of serum ceruloplasmin (P=0.034). 2975C>T (Pro992Leu) was correlated with earlier age of disease onset (P=0.002). Additionally, we found that the 3809A>G (Asn1270Ser) mutation significantly indicated younger onset age (P=0.012), and the 3884C>T (Ala1295Val) mutation at exon 18 was significantly associated with hepatic presentation (P=0.048). Moreover, the patients with mixed presentation displayed the initial WD features at an older onset age than the groups with either liver disease or neurological presentation (P=0.039, P=0.015, respectively). No significant difference was observed in the presence of KF rings among the three groups with different clinical manifestations. Conclusion In this study, we identified seven novel mutations in 103 WD patients from the southern part of China, which could enrich the previously established mutational spectrum of the ATP7B gene. Moreover, we tapped into a large-scale study of a Chinese WD cohort to characterise the overall phenotypic and genotypic spectra and assess the association between genotype and phenotype, which enhances the current knowledge about the population genetics of WD in China.

scholarly journals Attention Deficit Hyperactivity and Autism Spectrum Disorders as the Core Symptoms of AUTS2 Syndrome: Description of Five New Patients and Update of the Frequency of Manifestations and Genotype-Phenotype Correlation

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1360
Author(s):  
Carolina Sanchez-Jimeno ◽  
Fiona Blanco-Kelly ◽  
Fermina López-Grondona ◽  
Rebeca Losada-Del Pozo ◽  
Beatriz Moreno ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Attention Deficit ◽  
Autism Spectrum ◽  
Global Developmental Delay ◽  
Sequence Variants ◽  
Loss Of Function ◽  
Phenotype Correlation ◽  
Feeding Difficulties ◽  
Pathogenic Variants ◽  
Genotype Phenotype Correlation

Haploinsufficiency of AUTS2 has been associated with a syndromic form of neurodevelopmental delay characterized by intellectual disability, autistic features, and microcephaly, also known as AUTS2 syndrome. While the phenotype associated with large deletions and duplications of AUTS2 is well established, clinical features of patients harboring AUTS2 sequence variants have not been extensively described. In this study, we describe the phenotype of five new patients with AUTS2 pathogenic variants, three of them harboring loss-of-function sequence variants. The phenotype of the patients was characterized by attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) or autistic features and mild global developmental delay (GDD) or intellectual disability (ID), all in 4/5 patients (80%), a frequency higher than previously reported for ADHD and autistic features. Microcephaly and short stature were found in 60% of the patients; and feeding difficulties, generalized hypotonia, and ptosis, were each found in 40%. We also provide the aggregated frequency of the 32 items included in the AUTS2 syndrome severity score (ASSS) in patients currently reported in the literature. The main characteristics of the syndrome are GDD/ID in 98% of patients, microcephaly in 65%, feeding difficulties in 62%, ADHD or hyperactivity in 54%, and autistic traits in 52%. Finally, using the location of 31 variants from the literature together with variants from the five patients, we found significantly higher ASSS values in patients with pathogenic variants affecting the 3′ end of the gene, confirming the genotype-phenotype correlation initially described.

scholarly journals A Genotype-Phenotype Correlation of Haemophilia a in Victorian Patients with a Description of Novel Mutations

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2498-2498
Author(s):  
Shreerang Sirdesai ◽  
Kerryn Weekes ◽  
Asif Alam ◽  
Huyen A Tran ◽  
Christopher Barnes ◽  
...  
Keyword(s):  
In Silico ◽  
Family Members ◽  
In Silico Analysis ◽  
Clinical Severity ◽  
Missense Mutations ◽  
Phenotype Correlation ◽  
Novel Mutations ◽  
Mild Phenotype ◽  
Genotype Phenotype Correlation ◽  
Silico Analysis

Abstract Aim: Hemophilia A (HA) is caused by abnormalities in the Factor VIII gene. Certain abnormalities correlate with disease severity. Here, we report the genotype-phenotype correlation for all Victorian HA patients. Methods: Using the Australian Bleeding Disorders Registry, Victorian HA patients were identified. All genetic testing was conducted at Southern Health. The testing algorithm is summarized in Figure 1. Mutations were compared with the list of known Factor 8 mutations on the Champ and EAHAD F8 Variant Databases. A PubMed search was undertaken for any mutations not on either database. If this too was unrevealing, the mutation was designated novel. In-silico analysis was conducted on all novel mutations using three open-access, online prediction tools: a) Mutation Taster; b) Poly-Phen 2; c) Human Splice Site Predictor. Results: 318 patients with matched clinical and genetic records were identified. 275 had known FVIII mutations and 36 novel FVIII mutations were discovered. Eight patients (3%) had no mutations identified. (Table 1) In severe HA the intron-22 inversion was the most common mutation (47/122, 38%). Missense mutations predominated in mild and moderate HA. Inhibitors were present in 44/318 patients, the majority of whom had 26/44 (59%) severe HA. 20/36 novel mutations (55%) were associated with severe HA, 12/36 (33%) with mild HA and 4/36 (11%) with a moderate HA. Novel mutations associated with non-severe phenotypes were mostly missense mutations (15/16); More diversity was seen in the novel mutations causing a severe HA with a fairly even distribution of mutations: missense (7/20), nonsense (4/20) and small deletions and insertions (8/20). One large deletion involving a 6.5kb region of exon 26, as well as one duplication of exons 7 to 9 - was seen in the severe group. In-silico analysis predicted that all novel severe HA mutations were likely to be pathogenic.Inhibitors were seen in 7 patients with novel mutations. Of the 36 novel mutations we described, 9/36 (25%) were seen in other family members - often female carriers. All 9 mutations caused a severe phenotype which is not unexpected given that the screening and testing of family members would be unlikely to take place in patients who have a mild phenotype and rarely require supportive medical care Conclusion: This study adds 36 novel mutations to the currently known FVIII haemophilic mutations. It also confirms that the frequency and correlative clinical severity of known genetic mutations in the Victorian HA cohort is similar to that described internationally. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Analysis of Variants in the General Population Reveals That PMM2 Is Extremely Tolerant to Missense Mutations and That Diagnosis of PMM2-CDG Can Benefit from the Identification of Modifiers

2018 ◽  
Vol 19 (8) ◽  
pp. 2218 ◽  
Author(s):  
Valentina Citro ◽  
Chiara Cimmaruta ◽  
Maria Monticelli ◽  
Guglielmo Riccio ◽  
Bruno Hay Mele ◽  
...  
Keyword(s):  
General Population ◽  
Autosomal Recessive ◽  
Biochemical Analysis ◽  
Autosomal Recessive Disease ◽  
Type I ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Phenotype Correlation ◽  
Phenotypic Spectrum ◽  
Partial Deficiency

Type I disorders of glycosylation (CDG), the most frequent of which is phosphomannomutase 2 (PMM2-CDG), are a group of diseases causing the incomplete N-glycosylation of proteins. PMM2-CDG is an autosomal recessive disease with a large phenotypic spectrum, and is associated with mutations in the PMM2 gene. The biochemical analysis of mutants does not allow a precise genotype–phenotype correlation for PMM2-CDG. PMM2 is very tolerant to missense and loss of function mutations, suggesting that a partial deficiency of activity might be beneficial under certain circumstances. The patient phenotype might be influenced by variants in other genes associated with the type I disorders of glycosylation in the general population.

scholarly journals Factor VII deficiency: a novel missense variant and genotype–phenotype correlation in patients from Southern Italy

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Giovanni Tiscia ◽  
Giovanni Favuzzi ◽  
Elena Chinni ◽  
Donatella Colaizzo ◽  
Lucia Fischetti ◽  
...  
Keyword(s):  
Southern Italy ◽  
Missense Variant ◽  
Factor Vii ◽  
Phenotype Correlation ◽  
Factor Vii Deficiency ◽  
Genotype Phenotype Correlation

scholarly journals Evidence of mild founder LMOD3 mutations causing nemaline myopathy 10 in Germany and Austria

Neurology ◽  
2018 ◽  
Vol 91 (18) ◽  
pp. e1690-e1694 ◽  
Author(s):  
Ulrich A. Schatz ◽  
Simone Weiss ◽  
Stephan Wenninger ◽  
Benedikt Schoser ◽  
Wolfgang H. Muss ◽  
...  
Keyword(s):  
Early Death ◽  
Missense Variant ◽  
Nemaline Myopathy ◽  
Severe Form ◽  
Missense Mutations ◽  
Disease Course ◽  
Loss Of Function ◽  
Mild Disease ◽  
Upper Austria ◽  
Severe Clinical Picture

ObjectiveTo expand the clinical and genetic spectrum of nemaline myopathy 10 by a series of Austrian and German patients with a milder disease course and missense mutations in LMOD3.MethodsWe characterized the clinical features and the genetic status of 4 unrelated adolescent or adult patients with nemaline myopathy.ResultsThe 4 patients showed a relatively mild disease course. They all have survived into adulthood, 3 of 4 have remained ambulatory, and all showed marked facial weakness. Muscle biopsy specimens gave evidence of nemaline bodies. All patients were unrelated but originated from Austria (Tyrol and Upper Austria) and Southern Germany (Bavaria). All patients carried the missense variant c.1648C>T, p.(Leu550Phe) in the LMOD3 gene, either on both alleles or in trans with another missense variant (c.1004A>G, p.Gln335Arg). Both variants were not reported previously.ConclusionsIn 2014, a severe form of congenital nemaline myopathy caused by disrupting mutations in LMOD3 was identified and denoted as NEM10. Unlike the previously reported patients, who had a severe clinical picture with a substantial risk of early death, our patients showed a relatively mild disease course. As the missense variant c.1648C>T is located further downstream compared to all previously published LMOD3 mutations, it might be associated with higher protein expression compared to the reported loss-of-function mutations. The apparent clusters of 2 mild mutations in Germany and Austria in 4 unrelated families may be explained by a founder effect.

scholarly journals Unified inference of missense variant effects and gene constraints in the human genome

2019 ◽  
Author(s):  
Yi-Fei Huang
Keyword(s):  
Negative Selection ◽  
Random Effect ◽  
Evolutionary Model ◽  
Missense Variant ◽  
Autism Spectrum ◽  
Human Populations ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Selective Constraints ◽  
Gene Level

A challenge in medical genomics is to identify variants and genes associated with severe genetic disorders. Based on the premise that severe, early-onset disorders often result in a reduction of evolutionary fitness, several statistical methods have been developed to predict pathogenic variants or constrained genes based on the signatures of negative selection in human populations. However, we currently lack a statistical framework to jointly predict deleterious variants and constrained genes from both variant-level features and gene-level selective constraints. Here we present such a unified approach, UNEECON, based on deep learning and population genetics. UNEECON treats the contributions of variant-level features and gene-level constraints as a variant-level fixed effect and a gene-level random effect, respectively. The sum of the fixed and random effects is then combined with an evolutionary model to infer the strength of negative selection at both variant and gene levels. Compared with previously published methods, UNEECON shows unmatched performance in predicting missense variants and protein-coding genes associated with autosomal dominant disorders, and feature importance analysis suggests that both gene-level selective constraints and variant-level predictors are important for accurate variant prioritization. Furthermore, based on UNEECON, we observe an unexpected low correlation between gene-level intolerance to missense mutations and that to loss-of-function mutations, which can be partially explained by the prevalence of disordered protein regions that are highly tolerant to missense mutations. Finally, we show that genes intolerant to both missense and loss-of-function mutations play key roles in the central nervous system and the autism spectrum disorders. Overall, UNEECON is a promising framework for both variant and gene prioritization.

Sign in / Sign up

Export Citation Format

Share Document