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Background & objectives: Lysosomal storage disorders (LSDs) are genetic metabolic disorders which result from deficiency of lysosomal enzymes or defects in other lysosomal components. Molecular genetic testing of LSDs is required for diagnostic confirmation when lysosomal enzyme assays are not available or not feasible to perform, and for the identification of the disease causing genetic variants. The aim of this study was to develop a cost-effective, readily customizable and scalable molecular genetic testing strategy for LSDs. Methods: A testing method was designed based on the in-house creation of selective amplicons through long range PCR amplification for targeted capture and enrichment of different LSD genes of interest, followed by next generation sequencing of pooled samples. Results: In the first phase of the study, standardization and validation of the study protocol were done using 28 samples of affected probands and/or carrier parents (group A) with previously identified variants in seven genes, and in the second phase of the study, 30 samples of enzymatically confirmed or biopsy-proven patients with LSDs and/or their carrier parents who had not undergone any prior mutation analysis (group B) were tested and the sequence variants identified in them through the study method were validated by targeted Sanger sequencing. Interpretation & conclusions: This testing approach was found to be reliable, easily customizable and cost-effective for the molecular genetic evaluation of LSDs. The same strategy may be applicable, especially in resource poor settings, for developing cost-effective multigene panel tests for other conditions with genetic heterogeneity.
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Background & objectives: Calcium and vitamin D, separately or in combination are usually prescribed to prevent fragility fractures in elderly population. However, there are conflicting results regarding the ideal dosage and overall efficacy obtained from randomized controlled trials (RCTs) conducted in the past. The objective of this study was to assess the fracture risk with the administration of calcium or vitamin D alone or in combination in elderly population (>60 yr). Methods: PubMed, Cochrane and Embase databases were searched to identify the studies from inception to February 2021 with keywords, ‘vitamin D’, ‘calcium’ and ‘fracture’ to identify RCTs. The trials with comparing vitamin D, calcium or combination with either no medication or placebo were included for final analyses. The data were extracted and the study quality was assessed by two reviewers. The principal outcome measure was fractures around hip joint and secondary outcomes assessed were vertebral and any other fracture. Results: Eighteen RCTs were considered for the final analysis. Neither calcium nor vitamin D supplementation was associated with risk of fractures around hip joint [risk ratio (RR) 1.56; 95% confidence interval (CI), 0.91 to 2.69, I2=28%; P=0.11]. In addition, the combined administration of calcium and vitamin D was also not associated with fractures around the hip joint in comparison to either no treatment or placebo. The incidence of vertebral (RR 0.95; 95% CI, 0.82 to 1.10, I2=0%; P=0.49) or any other fracture (RR 0.83; 95% CI 0.65 to 1.06, I2=0%; P=0.14) was not significantly associated with the administration of calcium and vitamin D either individually or in combination. Further subgroup analysis of the results did not vary with the dosage of calcium or vitamin D, dietary calcium intake sex, or serum 25-hydroxyvitamin D levels. Interpretation & conclusions: The present meta-analysis of RCTs on calcium, vitamin D or a combination of the two in comparison to no treatment or placebo did not support the routine administration protocol of calcium and vitamin D either alone or in combination to lower the risk of fractures in elderly population.
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Genomics is an integral part of many pediatric diseases spanning all sub-specialities. While many genetic disorders are diagnosed with the currently available genomic tests, there still are many patients who do not receive a definitive diagnosis. The Indian Undiagnosed Diseases Program is a multicenter effort to address these challenges and unmet needs of rare disease patients where current available genetic tests have failed to make a diagnosis. It embodies the principles of collaborative effort across multispecialty disciplines, and uses detailed phenotype. Diagnostic methods are tailored to patient specifics and the large genomic data is interrogated with precise, in-house bioinformatics pipelines using patient-specific phenotype to build the diagnostic algorithm. The inception of this research initiative in India is a step towards creating awareness and appreciation of the needs for our undiagnosed cohorts to enable appropriate management in this era of precision medicine.
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Objective: To assess the utility of computer-aided facial analysis in identifying dysmorphicsyndromes in Indian children. Methods: Fifty-one patients with a definite molecular orcytogenetic diagnosis and recognizable facial dysmorphism were enrolled in the study andtheir facial photographs were uploaded in the Face2Gene software. The results provided bythe software were compared with the molecular diagnosis. Results: Of the 51 patients, thesoftware predicted the correct diagnosis in 37 patients (72.5%); predicted as the first in thetop ten suggestions in 26 (70.2%). In 14 patients, the software did not suggest a correctdiagnosis. Conclusions: Computer-aided facial analysis is a method that can aid indiagnosis of genetic syndromes in Indian children. As more clinicians start to use thissoftware, its accuracy is expected to improve.
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Objective: To study the histopathological characteristics and mutation spectrum of patientspresenting with the Duchenne muscular dystrophy (DMD) phenotype. Methods: This wasa descriptive study conducted over a period of 8 years. Multiplex ligation-dependent probeamplification (MLPA) was done in patients presenting with the DMD phenotype. If MLPA wasnegative, patients were offered muscle biopsy for histopathological studies and/or nextgeneration sequencing (NGS) based multigene panel testing for muscular dystrophies.Results: Of the 510 patients included, mutation in the DMD gene was detected by MLPA in372 (72.9%), of whom 342 (67.1%) had exonic deletions and 30 (5.9%) had exonicduplications. Exons 45-55 were most commonly involved in large deletions and exons 1-10were the commonest exons involved in duplications. In the MLPA-negative cohort, 27proceeded for muscle biopsy. NGS was done in 14 patients, 10 of whom had pathogenicmutations in the DMD gene, 3 were non dystrophinopathies and no pathogenic variant couldbe identified in one patient. Conclusions: For patients presenting with the DMD phenotype,MLPA of the DMD gene has a high diagnostic rate of about 73%, and non-dystrophinopathies may constitute a small but significant proportion.
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Justification: Gaucher disease (GD) is amongst the most frequently occurring lysosomal storage disorder in all ethnicities. The clinicalmanifestations and natural history of GD is highly heterogeneous with extreme geographic and ethnic variations. The literature on GD haspaucity of information and optimal management guidelines for Indian patients.Process: Gaucher Disease Task Force was formed under the auspices of the Society for Indian Academy of Medical Genetics. Invitedexperts from various specialties formulated guidelines for the management of patients with GD. A writing committee was formed andthe draft guidelines were circulated by email to all members for comments and inputs. The guidelines were finalized in December 2016at the annual meeting of the Indian Academy of Medical Genetics.Objectives: These guidelines are intended to serve as a standard framework for treating physicians and the health care systems foroptimal management of Gaucher disease in India and to define unique needs of this patient population.Recommendations: Manifestations of GD are protean and a high index of suspicion is essential for timely diagnosis. Patients frequentlyexperience diagnostic delays during which severe irreversible complications occur. Leucocyte acid ?-glucosidase activity ismandatory for establishing the diagnosis of Gaucher disease; molecular testing can help identify patients at risk of neuronopathicdisease. Enzyme replacement therapy for type 1 and type 3 Gaucher disease is the standard of care. Best outcomes are achieved byearly initiation of therapy before onset of irreversible complications. However, in setting of progressive neurological symptoms such asseizures and or/ neuroregression, ERT is not recommended, as it cannot cross the blood brain barrier. The recommendations herein arefor diagnosis, for initiation of therapy, therapeutic goals, monitoring and follow up of patients. We highlight that prevention of recurrenceof the disease through genetic counseling and prenatal diagnosis is essential in India, due to uniformly severe phenotypes encounteredin our population
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Background & objectives: Mucopolysaccharidosis type VI (MPS VI) is a rare, autosomal recessive lysosomal storage disorder caused by deficient enzymatic activity of N-acetyl galactosamine-4-sulphatase resulting from mutations in the arylsulphatase B (ARSB) gene. The ARSB gene is located on chromosome 5q11-q13 and is composed of eight exons. More than hundred ARSB mutations have been reported so far, but the mutation spectrum of MPS VI in India is still unknown. Hence, the aim of the present study was to identify the mutational spectrum in patients with MPS VI in India and to study the genotype-phenotype association and functional outcomes of these mutations. Methods: Molecular characterization of the ARSB gene by Sanger sequencing was done for 15 patients (aged 15 months to 11 yr) who were enzymatically confirmed to have MPS VI. Age of onset, clinical progression and enzyme activity levels in each patient were studied to look for genotype-phenotype association. Haplotype analysis performed for unrelated patients with the recurring mutation W450C, was suggestive of a founder effect. Sequence and structural analyses of the ARSB protein using standard software were carried out to determine the impact of detected mutations on the function of the ARSB protein. Results: A total of 12 mutations were identified, of which nine were novel mutations namely, p.D53N, p.L98R, p.Y103SfsX9, p.W353X, p.H393R, p.F166fsX18, p.I220fsX5, p.W450L, and p.W450C, and three were known mutations (p.D54N, p.A237D and p.S320R). The nine novel sequence variants were confirmed not to be polymorphic variants by performing sequencing in 50 unaffected individuals from the same ethnic population. Interpretation & conclusions: Nine novel mutations were identified in MPS VI cases from India in the present study. The study also provides some insights into the genotype-phenotype association in MPS VI.
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Background & objectives: Camptodactyly – arthropathy- coxa vara- pericarditis (CACP) syndrome is an autosomal recessive disorder caused by mutations in the PRG4 (proteoglycan 4) gene. Hallmarks of the syndrome include congenital or early-onset camptodactyly and arthropathy with synovial hyperplasia, progressive coxa vara deformity and non-inflammatory pericardial effusions. Till date only around 25 pathogenic mutations have been reported in this gene and none have been reported from India. We report here the mutations in the PRG4 gene in three patients of CACP from two unrelated families from India. Methods: Molecular genetic studies were done for the three patients with the CACP syndrome, from two unrelated Indian families, through sequence analysis of all coding exons and the exon-intron boundaries of the PRG4 gene. Results: Two novel frame-shift deletion mutations leading to premature protein termination were found. One patient was identified to be homozygous for a 2 base pair deletion in exon 6 (c.2645_2646delGA) and the two affected siblings from the other family were found to be homozygous for a 4 base pair deletion in exon 6 (c.2883_2886delAAGA). Conclusions: This is perhaps the first report of PRG4 mutations from India. Further mutation studies in Indian CACP cases will help to determine the mutation spectrum of the PRG4 gene in the Indian population and also help to further elucidate the molecular pathology and the genotype-phenotype correlation of this rare disease.
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Background: There is limited literature available on the phenotypic and mutation spectrum of Indian patients with Lysosomal storage disorders (LSD). Objective: To elucidate the clinical, biochemical and mutation spectrum and to study the management options in Indian patients with lysosomal storage disorders. Design: Descriptive study. Subjects and Methods: All patients with lysosomal storage disorders diagnosed in the Medical Genetics department of a tertiary care institute in North India over a three year period from January 2008 to December 2010. Results: Out of the total of 93 patients clinically suspected to have LSDs, 68 (mean age at presentation 4.5 years) were confirmed to have LSDs based on the laboratory/neuroimaging findings and documentation of deficient enzymatic activity in the peripheral blood (leucocytes or plasma) and/or skin fibroblasts. The commonest clinical features at presentation were growth retardation (failure to thrive 47.2% and short stature 17.6%), hepatosplenomegaly (41.2%) and neuroregression (33.8%). A history of consanguinity was present in 32.4% of the families. Prenatal diagnosis was done in a total of 6 affected families; two pregnancies were found to be affected (one each with Gaucher disease and Tay Sachs disease) and in both cases the parents opted for termination of pregnancy. Of the remaining four pregnancies which were found to be unaffected and therefore continued, three were confirmed to be normal on post-natal follow up. Enzyme replacement therapy (ERT) is being given for a total of 8 LSD patients and all of them are showing a gradual amelioration of their symptoms and an improvement in the quality of life. Conclusions: Lysosomal storage disorders constitute an important group of genetic metabolic disorders for many of which therapeutic options are now available.
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CONTEXT: Multiplex ligation probe amplification (MLPA) is a new technique to identify deletions and duplications and can evaluate all 79 exons in dystrophin gene in patients with Duchenne muscular dystrophy (DMD). Being semi-quantitative, MLPA is also effective in detecting duplications and carrier testing of females; both of which cannot be done using multiplex PCR. It has found applications in diagnostics of many genetic disorders. AIM: To study the utility of MLPA in diagnosis and carrier detection for DMD. MATERIALS AND METHODS: Mutation analysis and carrier detection was done by multiplex PCR and MLPA and the results were compared. RESULTS AND CONCLUSIONS: We present data showing utility of MLPA in identifying mutations in cases with DMD/BMD. In the present study using MLPA, we identified mutations in additional 5.6% cases of DMD in whom multiplex PCR was not able to detect intragenic deletions. In addition, MLPA also correctly confirmed carrier status of two obligate carriers and revealed carrier status in 6 of 8 mothers of sporadic cases.
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Distrofina , Femenino , Humanos , Masculino , Proteínas de la Membrana/análisis , Reacción en Cadena de la Polimerasa Multiplex/métodos , Distrofia Muscular de Duchenne/genética , Reacción en Cadena de la Polimerasa/métodosRESUMEN
We report a case of partial monosomy 7q and partial trisomy 14q in a 4 year old male with microcephaly, prominent eyes, arched eyebrows, malformed ears and overlapping of toes. The unbalanced rearrangement resulted in monosomy of 7q33qter and trisomy of 14q32.2qter. The clinical phenotype was similar to the other cases of 7q deletion.
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OBJECTIVE: Angiotensin-converting enzyme plays an important role in maintaining blood pressure, while methylenetetrahydrofolate reductase is involved in homocysteine metabolism. As hypertension and elevated homocysteine levels are among the various risk factors for coronary artery disease, the two polypeptides might need to be considered while determining the risk. Our study aimed to assess the association between common polymorphisms in these genes and susceptibility to coronary artery disease. METHODS: We studied 268 north Indian individuals with coronary artery disease and 90 age-matched controls. The distribution of the genotypes and allele frequencies of both genes were analyzed using polymerase chain reaction amplification and restriction fragment length polymorphism analysis. RESULTS: The frequency of the D allele was significantly higher among the patients (62%) than the controls (44%) (p=0.001, odds ratio=2.06). The same goes for the DD genotype (37% vs 21%) (p=0.004). The combined frequency of the D allele carriers was significantly higher among patients of coronary heart disease, with a difference of 20% (85% vs 65%) (p=0.003, odds ratio=3.1; CI: 1.3-7.29). However, the frequency of the T and C alleles, as well as that of the CC, CT and TT genotypes of the methylenetetrahydrofolate reductase gene, did not differ significantly between the two groups. CONCLUSION: We conclude that coronary artery disease in north Indian patients is strongly associated with the carrier state of the angiotensin-converting enzyme D allele, but not with the C677T transition in the methylenetetrahydrofolate reductase gene.
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Adulto , Anciano , Enfermedad de la Arteria Coronaria/genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Metilenotetrahidrofolato Deshidrogenasa (NADP)/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Persona de Mediana Edad , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético/genética , Adulto JovenRESUMEN
OBJECTIVE: Hemihyperplasia is a heterogenous group of disorders characterized by asymmetric limb growth. There is considerable confusion regarding their classification and ascertainment into various syndromes. We tried to look into the various aspects of hemihyperplasia syndromes. METHODS: Records of 17 consecutive cases of hemihyperplasia were reviewed and were ascertained into various syndromes based on available literature and diagnostic criteria. RESULTS: Of the 17 cases with hemihyperplasia, 3 cases satisfied the diagnostic criteria for Proteus syndrome. One patient each was ascertained as Klippel Trenaunay Weber syndrome and Hemihyperplasia- Multiple lipomatosis. 9 cases were classified as isolated hemihyperplasia. We found two novel associations with hemihyperplasia; namely Ehlers-Danlos syndrome like skin changes and Poland anomaly on the affected side. The remaining 3 cases had miscellaneous disorders with limb asymmetry, namely Neurofibromatosis Type I in 2 cases and Olliers disease in one case. CONCLUSION: Efforts to diagnose syndromes of hemihyperplasia help in genetic counseling.