scholarly journals Homozygous p.Val89Leu plays an important pathogenic role in 5α-reductase type 2 deficiency patients with homozygous p.Arg246Gln in SRD5A2

2020 ◽  
Vol 183 (3) ◽  
pp. 275-284
Author(s):  
Sneha Arya ◽  
Ankita Tiwari ◽  
Anurag Ranjan Lila ◽  
Vijaya Sarathi ◽  
Vishwambhar Vishnu Bhandare ◽  
...  
Keyword(s):  
Md Simulation ◽  
Pathogenic Variant ◽  
Additional Contribution ◽  
Homozygous State ◽  
Pathogenic Role ◽  
T Complex ◽  
Pathogenic Variants ◽  
Design And Methods

Objective: To evaluate the pathogenic role of a few benign variants and hypomorphic pathogenic variants in SRD5A2. Design and methods: We retrospectively analyzed phenotypes and genotypes in 23 Indian patients with genetically proven steroid 5α-reductase 2 (SRD5A2) deficiency. The interactions of the SRD5A2 enzymes resulting due to the most common benign variant (p.Val89Leu), the most common (hypomorphic) pathogenic variant (p.Arg246Gln) and the double variants (p.Val89Leu and p.Arg246Gln) in SRD5A2 were compared with that of the wild type (WT) enzyme by molecular dynamics (MD) simulation. Results: The majority (n = 19, 82.61%) of patients presented for atypical genitalia and had male gender identity (16/20). Including the two novel ones (p.Leu83Pro, p.Ala28Leufs*103), a total of nine different pathogenic variants were observed. p.Arg246Gln was the most common pathogenic variant (n = 12). Homozygous p.Arg246Gln (n = 9) variant was associated with milder undervirilization (Sinnecker score of ≤3a: 8/9 vs 6/14, P = 0.04) and had concurrent homozygous p.Val89Leu in all patients. Interestingly, asymptomatic fathers of two index patients were homozygous for p.Arg246Gln which questioned the pathogenicity of the variation as a sole factor. Unlike all symptomatic homozygous p.Arg246Gln patients who were also homozygous for p.Val89Leu, asymptomatic homozygous p.Arg246Gln fathers were heterozygous for p.Val89Leu. On MD simulation SRD5A2 p.Val89Leu-Testeosterone (T) and SRD5A2 p.Arg246Gln-T complexes, but not SRD5A2 p.Val89Leu and p.Arg246Gln-T complex, demonstrated close interaction between NADPH and T as that of SRD5A2 WT-T. Conclusions: p.Arg246Gln may not be pathogenic as a sole variation even in the homozygous state; additional contribution of homozygous p.Val89Leu variant may be essential for the pathogenicity of p.Arg246Gln in SRD5A2.

scholarly journals A Novel SRY Pathogenic Variant from a 46,XY Female Harboring a Nonsense Point Mutation (G to A) in Position 293

2021 ◽  
Author(s):  
Shengfang Qin ◽  
Xueyan Wang ◽  
Yunxing Li
Keyword(s):  
Point Mutation ◽  
Gene Mutation ◽  
Molecular Diagnosis ◽  
Novel Mutation ◽  
Pathogenic Variant ◽  
Sry Gene ◽  
Pathogenic Role ◽  
Common Cause ◽  
Xy Female

SRY gene mutation is a common cause of 46,XY female. We report a 46,XY female with a novel mutation of SRY c.293G>A (p.Trp98ter). Our report provides evidence for a pathogenic role of the SRY gene c.293G>A mutation in an individual and enlarges the spectrum of molecular diagnosis for these patients.

scholarly journals Geographical Variation in the profile of RET Variants in Patients with Medullary Thyroid Cancer: A Comprehensive Review

2021 ◽  
Author(s):  
Rui M. B. Maciel ◽  
Ana Luiza Maia
Keyword(s):  
Haplotype Analysis ◽  
Medullary Thyroid Cancer ◽  
Genetic Diagnosis ◽  
Epidemiological Data ◽  
Global Perspective ◽  
Causative Role ◽  
Medullary Thyroid ◽  
Pathogenic Variants

Genetic variability in humans is influenced by many factors, such as natural selection, mutations, genetic drift, and migrations. Molecular epidemiology evaluates the contribution of genetic risk factors in the etiology, diagnosis, and prevention of a particular disease. Few areas of medicine have been so clearly affected by genetic diagnosis and management as multiple neoplasia type 2 (MEN2), in which activating pathogenic variants in the RET gene results in the development of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism in nearly 98%, 50% and 25% of gene carriers, respectively. Here, we aimed to collect RET genotyping data worldwide to analyze the distribution and frequency of RET variants from a global perspective. We show that the mutational spectrum of RET is observed worldwide. The codon 634 variants seem to be the most prevalent, but there are differences in the type of amino acid exchanges among countries and in the frequencies of the other RET codon variants. Most interestingly, studies using haplotype analysis or pedigree linkage have demonstrated that some pathogenic RET variants have been transmitted to offspring for centuries, explaining some local prevalence due to a founder effect. Unfortunately, after almost three decades after the causative role of the germline RET variants have been reported in hereditary MTC, comprehensive genotyping data remain limited to a few countries. The heterogeneity of RET variants justifies the need for a global effort to describe epidemiological data of families with MEN2 to further understand the genetic background and environmental circumstances that affect disease presentation.

scholarly journals Profibrotic circulating proteins and risk of early progressive renal decline in Type 2 Diabetes patients with and without albuminuria

2020 ◽  
Author(s):  
Katsuhito Ihara ◽  
Jan Skupien ◽  
Hiroki Kobayashi ◽  
Zaipul I. Md Dom ◽  
Jonathan M. Wilson ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Core Domain ◽  
Fibrotic Process ◽  
Baseline Levels ◽  
Design And Methods ◽  
Circulating Levels ◽  
Index Combination

<b>OBJECTIVE</b>: The role of fibrosis in early progressive renal decline in type 2 diabetes is unknown. Circulating WFDC2 (WAP four-disulfide core domain protein 2) and MMP-7 (Matrilysin) are postulated to be biomarkers of renal fibrosis. This study examined an association of circulating levels of these proteins with early progressive renal decline. <p><b>RESEARCH DESIGN AND METHODS</b>: Individuals with type 2 diabetes enrolled in the Joslin Kidney Study with eGFR ≥60 ml/min/1.73m<sup>2</sup> were followed for 6-12 years to ascertain fast early progressive renal decline defined as eGFR loss ≥5 ml/min/1.73m<sup>2</sup>/year. </p> <p><b>RESULTS</b>: A total of 1,181 individuals were studied: 681 without and 500 with albuminuria. Median eGFR and ACR at baseline were 97 ml/min/1.73m<sup>2</sup> and 24 mg/g, respectively. During follow-up, 152 individuals experienced fast early progressive renal decline: 6.9% in those with normoalbuminuria and 21% with albuminuria. In both subgroups risk of renal decline increased with increasing baseline levels of WFDC2 (p <0.0001) and MMP-7 (p <0.0001). After adjustment for relevant clinical characteristics and known biomarkers, an increase by one quartile in the Fibrosis Index (combination of levels of WFDC2 and MMP-7) was associated with higher risk of renal decline (OR 1.63; 95% CI 1.30-2.04). The association was similar and statistically significant among patients with and without albuminuria. </p> <p><b>CONCLUSIONS: </b>Elevation of circulating profibrotic proteins is associated with the development of early progressive renal decline in type 2 diabetes. This association is independent from albuminuria status and points to the importance of the fibrotic process in development of early renal decline. </p>

scholarly journals UNUSUAL PRESENTATIONS OF LMNA-ASSOCIATED LIPODYSTROPHY WITH COMPLEX PHENOTYPES AND GENERALIZED FAT LOSS: WHEN THE GENETIC DIAGNOSIS UNCOVERS NOVEL FEATURES

2020 ◽  
Vol 6 (2) ◽  
pp. e79-e85
Author(s):  
Natalia Xavier S. de Andrade ◽  
Suleyman Cem Adiyaman ◽  
Berna Demir Yuksel ◽  
Carla T. Ferrari ◽  
Abdelwahab Jalal Eldin ◽  
...  
Keyword(s):  
Genetic Diagnosis ◽  
Pathogenic Variant ◽  
The Body ◽  
Muscle Disease ◽  
Partial Lipodystrophy ◽  
Fat Loss ◽  
Pathogenic Variants ◽  
Complex Phenotypes ◽  
Familial Partial Lipodystrophy

Objective: Lipodystrophy represents a group of rare diseases characterized by loss of body fat. While patients with generalized lipodystrophy exhibit near-total lack of fat, partial lipodystrophy is associated with selective fat loss affecting certain parts of the body. Although classical familial partial lipodystrophy (FPLD) is a well-described entity, recent reports indicate phenotypic heterogeneity among carriers of LMNA pathogenic variants. Methods: We have encountered 2 unique cases with complex phenotypes, generalized fat loss, and very low leptin levels that made the distinction between generalized versus partial lipodystrophy quite challenging. Results: We present a 61-year-old female with generalized fat loss, harboring the heterozygous pathogenic variant p.R541P (c.1622G>C) on the LMNA gene. The discovery of the pathogenic variant led to correct clinical diagnosis of her muscle disease, identification of significant heart disease, and a recommendation for the implantation of a defibrillator. She was able to start metreleptin based on her generalized fat loss pattern and demonstration of the genetic variant. Secondly, we report a 40-year-old Turkish female with generalized fat loss associated with a novel heterozygous LMNA pathogenic variant p.K486E (c.1456A>G), who developed systemic B cell follicular lymphoma. Conclusion: Clinicians need to recognize that the presence of an LMNA variant does not universally lead to FPLD type 2, but may lead to a phenotype that is more complex and may resemble more closely generalized lipo-dystrophy. Additionally, providers should recognize the multisystem features of laminopathies and should screen for these features in affected patients, especially if the variant is not at the known hotspot for FPLD type 2.

P1247FLNC pathogenic variants in patients with various cardiomyopathies:prevalence and genotype-phenotype correlations

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
F Ader ◽  
P De Groote ◽  
P Reant ◽  
D Dupin-Deguine ◽  
C Rambaud ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Cardiac Death ◽  
Left Ventricular ◽  
Pathogenic Variant ◽  
Pathogenic Variants ◽  
History Of ◽  
Custom Panel ◽  
Few Data ◽  
First Time

Abstract Background/Introduction Pathogenic variants FLNC encoding filamin C have been firstly reported to cause myopathies, and were recently linked to isolated cardiac phenotypes.However, few data on phenotype-genotype correlation are available. Purpose Our aim was to estimate the prevalence of FLNC pathogenic variants in cardiomyopathies and to study the relations between phenotype and genotype. Methods DNAs from a cohort of 1150 unrelated index-patients with an isolated cardiomyopathy (700 hypertrophic, 300 dilated, 50 restrictive cardiomyopathies, and 100 left ventricle non-compactions) have been sequenced on a custom panel of 52 cardiomyopathy disease-causing genes. Results A FLNC pathogenic variant was identified in 28 patients corresponding to a prevalence ranging from 1 to 8% depending on the cardiomyopathy subtypes. Truncating variants were always identified in patients with dilated cardiomyopathy, while missense or in-frame variants were found in other phenotypes. This work reported for the first time a left ventricular non-compaction associated with FLNC pathogenic variant. In the cohort, nine patients (32%) were implanted with an automatic defibrillator. In 7 families (25%), history of sudden cardiac death (SCD) before 50 years was reported. A personal or family history of sudden cardiac death (SCD) was significantly higher in patients with truncating variants than in patients carrying missense variants (p=0.01). Four patients died of cardiac cause including 3 from SCD and 1 from heart failure. Conclusion This work highlights the role of FLNC in cardiomyopathies. A correlation between the type of the variant and the cardiomyopathy subtype was observed as well as with SCD risk. These new data should be taken into consideration for patient's management and primary prevention of sudden cardiac death. Acknowledgement/Funding La ligue contre la Cardiomyopathie

scholarly journals SUN-600 Presence of LMNA p.R582H Pathogenic Variant in Homozygous State Demonstrates Gene Dosage Effect on the Severity of Fat Loss in Lipodystrophy

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Utku Erdem Soyaltin ◽  
Ilgin Yildirim Simsir ◽  
Baris Akinci ◽  
Canan Altay ◽  
Suleyman Cem Adiyaman ◽  
...  
Keyword(s):  
Gene Dosage ◽  
Pathogenic Variant ◽  
Dosage Effect ◽  
Lamin A ◽  
Lmna Gene ◽  
Homozygous State ◽  
Gene Dosage Effect ◽  
Fat Loss ◽  
Genital Region ◽  
Pathogenic Variants

Abstract Background Classical heterozygous pathogenic variants of the lamin A/C (LMNA) gene cause familial partial lipodystrophy type 2 (FPLD2). However, recent reports indicate phenotypic heterogeneity among carriers of LMNA pathogenic variants, and a few patients have been associated with generalized fat loss. Clinical Case Here, we report a patient with lamin A specific pathogenic variant at exon 11 LMNA p.R582H present in homozygous state. Fat distribution was compared radiographically to a heterozygote LMNA p.R582H patient from another pedigree, female healthy control, a series of adult female subjects with congenital generalized lipodystrophy type 1 (CGL1, n = 9) and typical FPLD2 (n = 8). The whole body MRI of the index case confirmed near-total loss of subcutaneous adipose tissue with well-preserved fat in the retroorbital area, palms and soles, mons pubis, and external genital region. This pattern resembled the fat loss pattern observed in CGL1 with only one difference: strikingly more fat was observed around mons pubis and the genital region. Also, homozygous p.R582H LMNA variant was associated with lower leptin level and earlier onset of metabolic abnormalities compared to heterozygous p.R582H variant and typical FPLD2 cases. On the other hand, heterozygous LMNA p.R582H variant was associated with partial fat loss which was similar to typical FPLD2 but less severe than the patients with the hot-spot variants at position 482. Conclusions Our observations and radiological comparisons demonstrate a gene dosage effect of LMNA variants on the severity of fat loss and add to the body of evidence that there may be complex genotype-phenotype relationships in this interesting disease known as FPLD2. Although the pathological basis for fat loss is not well understood in patients harboring pathogenic variants in the LMNA gene, our observation suggests that genetic factors modulate the extent of fat loss in LMNA associated lipodystrophy.

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