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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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Justification: The diagnosis of Down syndrome (DS) is easily made clinically but the management is multi-disciplinary and life-long. There is no standard protocol available for its management in India. Process: A committee was formed under the Indian Academy of Pediatrics (IAP) chapter of Neuro developmental pediatrics consisting of 20 experts working in the related field. The various aspects of the condition were discussed and allotted to the concerned experts related for preparing the guidelines. The material received was collated to form a set of guidelines, which were reviewed by the committee, and a consensus statement made. The guidelines were then approved by the chapter, and by the IAP. Objectives: To define the condition and to look into the various aspects of antenatal and postnatal diagnosis. To explain briefly about the involvement of the various systems that are involved and formulate recommendations for management. To recommend early and sustained interventional therapies to enable children with DS lead an independent life. Recommendations: The stress on bio-psycho-social strategy for the management of children with DS is reiterated, and the need for a medical, social and rights model is recommended after each section. The age-wise recommendations are also highlighted in addition to the recommendations under each system.
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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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Hypertrichosis refers to the growth of hair, of an excessive amount and thickness, on any part of the body. It must be distinguished from hirsutism which is characterized by excess growth of hair in androgen-dependent areas on the upper lip, chin, chest, linea alba, thigh and axilla. Hypertrichosis may be localized or generalized, and congenital or acquired. Excess hair growth has a psychological impact on the child as well as the parents due to the cosmetic disfigurement it produces. Current treatment options are limited and not wholly satisfactory. Treatment should be customized according to the area, nature and amount of hair growth, age of the patient and personal preferences. In addition, when hypertrichosis occurs as a component of a syndrome, multidisciplinary management is required to address the associated systemic features. A detailed review of inherited generalized hypertrichosis is presented here with emphasis on clinical clues to identifying complex syndromes with multisystem involvement
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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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Background: Type V osteogenesis imperfecta is characterized by hyperplastic callus formation and interosseus membrane calcification. Case characteristics: A 16-year-old boy who presented with history of recurrent fractures, had hard persistent swellings at fracture sites, and had radiographic features of hyperplastic callus and interosseus membrane calcification. Outcome: Sequence analysis of the IFITM5 gene revealed the c.-14 C>T mutation. The patient had significant exacerbation of callus hyperplasia after initiation of bisphosphonate therapy, which reversed following cessation of the treatment. Message: Bisphosphonates may exacerbate callus hyperplasia, and may therefore have to be used with caution in patients with type V osteogenesis imperfecta.
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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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Background & objectives: Although clinical reports have described infantile malignant autosomal recessive osteopetrosis (ARO) in Indian patients, no published data are available about the genetic causes of ARO in this population. We investigated the main genetic causes of ARO in eight Indian patients with early postnatal onset and the typical severe clinical course including visual impairment and anaemia. Methods: Mutation screening in the genes CLCN7 and TCIRG1 was done on genomic DNA from 8 affected individuals (diagnosed on the basis of clinical and haematological parameters and characteristic radiological changes of increased bone density) and their parents. In one family, after detection of both mutations in the proband, targeted mutation analysis was also done in chorionic villus samples for prenatal diagnosis. Results: Six patients had mutations in TCIRG1 and two patients harboured mutations in CLCN7 gene. Three of the five different TCIRG1 mutations identified and both CLCN7 mutations were novel mutations. Except for the already known mutation p.Ile720del, all TCIRG1 mutations disrupt conserved splice consensus sequences or lead to premature stop codons. In contrast, both CLCN7 mutations only lead to missense changes of conserved amino acids. In a foetus harbouring TCIRG1 mutations osteopetrosis was visible radiologically at 23 wk of gestation. Interpretation & conclusions: That the CLCN7 mutations provoke a phenotype as severe as the one caused by TCIRG1 loss of function suggests the affected residues to be crucial for the function of the ClC-7 chloride channel or chloride/proton-exchanger. Our data also show that ARO can manifest as early as in the second trimester of pregnancy.