Lynch syndrome: An unusal case of familial cancer unearthed.

Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC) is a type of inherited cancer syndrome with a genetic predisposition to different types of cancer. There is an increased predisposition to cancers in the endometrium, colon, stomach, ovary, uterus, skin, kidney, and brain in patients of Lynch syndrome. We are reporting a 48-year-old male who presented with a pea-sized growth in his left arm which was found to be sebaceoma on histopathology. On further detailed history, examination, and genetic study, it was proved to be a familial case of Lynch syndrome. The case is being reported to stress the importance of knowledge about clinical manifestation, associated neoplasms, and molecular genetic profile of Lynch syndrome which will enable physicians and pathologists to provide highly targeted surveillance and management for patients with high cancer risk.

Determining Cost-Optimal Next-Generation Sequencing Panels for Rare Disease and Pharmacogenomics Testing.

BACKGROUND: Multi-gene panel sequencing using next-generation sequencing (NGS) methods is a key tool for genomic medicine. However, with an estimated 140 000 genomic tests available, current system inefficiencies result in high genetic-testing costs. Reduced testing costs are needed to expand the availability of genomic medicine. One solution to improve efficiency and lower costs is to calculate the most cost-effective set of panels for a typical pattern of test requests. METHODS: We compiled rare diseases, associated genes, point prevalence, and test-order frequencies from a representative laboratory. We then modeled the costs of the relevant steps in the NGS process in detail. Using a simulated annealing-based optimization procedure, we determined panel sets that were more cost-optimal than whole exome sequencing (WES) or clinical exome sequencing (CES). Finally, we repeated this methodology to cost-optimize pharmacogenomics (PGx) testing. RESULTS: For rare disease testing, we show that an optimal choice of 4-6 panels, uniquely covering genes that comprise 95% of the total prevalence of monogenic diseases, saves $257-304 per sample compared with WES, and $66-135 per sample compared with CES. For PGx, we show that the optimal multipanel solution saves $6-7 (27%-40%) over a single panel covering all relevant gene-drug associations. CONCLUSIONS: Laboratories can reduce costs using the proposed method to obtain and run a cost-optimal set of panels for specific test requests. In addition, payers can use this method to inform reimbursement policy.

Identification of potential lockdown areas during COVID-19 transmission in Punjab, Pakistan.

OBJECTIVES: Real-time COVID-19 spread mapping and monitoring to identify lockdown and semi-lockdown areas using hotspot analysis and geographic information systems and also near future prediction modeling for risk of COVID-19 in Punjab, Pakistan. STUDY DESIGN: Data for all COVID-19 cases were collected until 20 October 2020 in Punjab Province. METHODS: The methodology included geotagging COVID-19 cases to understand the trans-mobility areas for COVID-19 and characterize risk. The hotspot analysis technique was used to identify the number of areas in danger zones and the number of people affected by COVID-19. The complete lockdown areas were marked down geographically to be selected by the government of Pakistan based on increased numbers of cases. RESULTS: As per predictive model estimates, almost 9.2 million people are COVID-19 infected by 20 October 2020 in Punjab Province. The compound growth rate of COVID-19 decreased to 0.012% per day and doubling rate increased to 364.5 days in Punjab Province. Based on Pueyo model predictions from past temporal data, it is more likely that Punjab and Pakistan entered into peak around the first week of July 2020, and the decline of growth rate (and doubling rate) of reported cases started afterward. Hospital load was also measured through the Pueyo model, and mostly, people in the 60+ years age group are expected to dominate the hospitalized population. CONCLUSIONS: Pakistan is experiencing a high number of COVID-19 cases, with the maximum share from Punjab, Pakistan. Statistical modeling and compound growth estimation formulation were done through the Pueyo model, which was applied in Pakistan to identify the compound growth of COVID-19 patients and predicting numbers of patients shortly by slightly modifying it as per the local context.

Lipoprotein Lipase Deficiency.

OBJECTIVES: To analyse the clinical and molecular spectrum of Lipoprotein Lipase (LPL) deficiency and to highlight the effect of a cost-effective indigenous diet for management of this disorder. METHODS: This is a single-centre retrospective study. Fifteen patients from 14 kindreds with severe hypertriglyceridemia (more than 1000 mg/dl) were evaluated for a period of 12.5 y at Amrita Institute of Medical Sciences, Kerala, India. RESULTS: Thirteen of 15 patients were referred after incidental detection of lipemic plasma, 1/15 had chylothorax in the neonatal period and 1/15 had pancreatitis. The mean age of presentation was 7 mo (ranging from 2 d to 4 y), and 20% of the patients had a positive history of consanguinity. Hepatomegaly (15/15), splenomegaly (9/15) and lipemia retinalis (14/15) were common findings. Lipemia retinalis was a useful non-invasive diagnostic tool. All the patients were subjected to diet modification and followed up at regular intervals. Fourteen of 15 complied with the diet, resulting in a dramatic improvement in the fasting lipid profile; only 1/15 developed pancreatitis. Genetic screening analysis was offered to 14/15 patients (1/15 was lost to follow-up); six different variants were identified, of which two were novel variants. CONCLUSIONS: Lipemic serum, chylothorax and recurrent pancreatitis in children should raise the suspicion of Lipoprotein Lipase deficiency. Early diagnosis and prompt initiation of a stringent fat-restricted diet are the keys to success for the management of LPL deficiency and prevention of pancreatitis.

Assessing Utility of Clinical Exome Sequencing in Diagnosis of Rare Idiopathic Neurodevelopmental Disorders in Indian Population.

BACKGROUND: Neurological diseases are phenotypically and genotypically heterogeneous. Clinical exome sequencing (CES) has been shown to provide a high diagnostic yield for these disorders in the European population but remains to be demonstrated for the Indian population. OBJECTIVE: The study aimed to understand the utility of clinical exome sequencing for the diagnosis of neurodevelopmental disorders. MATERIALS AND METHODS: A cohort of 19 idiopathic patients with neurological phenotypes, primarily intellectual disability and developmental delay, were recruited. CES covering 4620 genes was performed on all patients. Candidate variants were validated by Sanger sequencing. RESULTS: CES in 19 patients provided identified 21 variants across 16 genes which have been associated with different neurological disorders. Fifteen variants were reported previously and 6 variants were novel to our study. Eleven patients were diagnosed with autosomal dominant de novo variants, 7 with autosomal recessive and 1 with X-linked recessive variants. CES provided definitive diagnosis to 10 patients; hence, the diagnostic yield was 53%. CONCLUSION: Our study suggests that the diagnostic yield of CES in the Indian population is comparable to that reported in the European population. CES together with deep phenotyping could be a cost-effective way of diagnosing rare neurological disorders in the Indian population.

Lethal Cenani Lenz syndrome in two consecutive pregnancies: Further extension of phenotype from Maldives.

Cenani Lenz syndrome is a rare autosomal recessive disorder associated with variable degree of limb malformations, dysmorphism, and renal agenesis. It is caused due to pathogenic variants in the LRP4 gene, which plays an important role in limb and renal development. Mutations in the APC gene have also been occasionally associated with CLS. The phenotypic spectrum ranges from mild to very severe perinatal lethal type depending on the type of variant. We report a pathogenic variant, c.2710 del T (p.Trp904GlyfsTer5) in theLRP4 gene, in a fetus with lethal Cenani Lenz syndrome with antenatal presentation of tetraphocomelia and symmetrical involvement of hands and feet.

Synaptic Nuclear Envelope Protein 1 (SYNE 1) Ataxia with Amyotrophic Lateral Sclerosis-like Presentation: A Novel Synaptic Nuclear Envelope Protein 1 (SYNE 1) Gene Deletion Mutation from India.

A 24-year-old female presented with wasting and weakness of both hands and fasciculations over the chin since 12 years, followed by imbalance while walking and speech changes since 10 years. Her 12-year-old sister also had a similar clinical presentation. There were fasciculations over the chin, tongue, hands, back, thighs with wasting and weakness in tongue, and C7, C8, T1 segments in both upper limbs along with bipyramidal signs. There was limb and gait ataxia. Magnetic resonance imaging brain showed pancerebellar atrophy, and electromyography was suggestive of anterior horn cell involvement in bulbar, cervical, thoracic, and lumbar segments. Next-generation sequencing identified a novel likely pathogenic deletion mutation: chr6:152527389_152527399del, c.22711_22721del, and p.Ala7571ArgfsTer4 in exon 125 of synaptic nuclear envelope protein 1 (SYNE1) gene. This mutation leads to frameshift and premature termination of the protein 'Nesprin 1'. Amyotrophic lateral sclerosis-like presentation followed by cerebellar ataxia have been described with SYNE1 ataxia. This unique phenotype and novel deletion mutation of SYNE1 gene is the first case reported from India.

Genetic Counseling, Testing, and Management of HBOC in India: An Expert Consensus Document from Indian Society of Medical and Pediatric Oncology.

PURPOSE: Hereditary breast and ovarian cancer (HBOC) syndrome is primarily characterized by mutations in the BRCA1/2 genes. There are several barriers to the implementation of genetic testing and counseling in India that may affect clinical decisions. These consensus recommendations were therefore convened as a collaborative effort to improve testing and management of HBOC in India. DESIGN: Recommendations were developed by a multidisciplinary group of experts from the Indian Society of Medical and Pediatric Oncology and some invited experts on the basis of graded evidence from the literature and using a formal Delphi process to help reach consensus. PubMed and Google Scholar databases were searched to source relevant articles. RESULTS: This consensus statement provides practical insight into identifying patients who should undergo genetic counseling and testing on the basis of assessments of family and ancestry and personal history of HBOC. It discusses the need and significance of genetic counselors and medical professionals who have the necessary expertise in genetic counseling and testing. Recommendations elucidate requirements of pretest counseling, including discussions on genetic variants of uncertain significance and risk reduction options. The group of experts recommended single-site mutation testing in families with a known mutation and next-generation sequencing coupled with multiplex ligation probe amplification for the detection of large genomic rearrangements for unknown mutations. Recommendations for surgical and lifestyle-related risk reduction approaches and management using poly (ADP-ribose) polymerase inhibitors are also detailed. CONCLUSION: With rapid strides being made in the field of genetic testing/counseling in India, more oncologists are expected to include genetic testing/counseling as part of their clinical practice. These consensus recommendations are anticipated to help homogenize genetic testing and management of HBOC in India for improved patient care.

Genotype-phenotype correlates of infantile-onset developmental & epileptic encephalopathy syndromes in South India: A single centre experience.

INTRODUCTION: A paucity of literature exists on genotype- phenotype correlates of 'unknown-etiology' infantile-onset developmental-epileptic encephalopathies (DEE) from India. The primary objective was to explore the yield of genetic testing in identifying potential disease causing variants in electro-clinical phenotypes of DEE METHODS: An observational hospital-based study was undertaken on children with unexplained refractory seizure-onset ≤12 months age and developmental delay, whose families consented and underwent genetic testing during a three year time period (2016-2018) by next-generation sequencing (NGS) or multiplex ligand protein amplification. Yield was considered based on demonstration of pathogenic/likely pathogenic variants only and variants of unknown significance (VUS) were documented. RESULTS: Pathogenic/likely pathogenic variants were identified in 26 (31.7 %) out of 82 children with DEE. These included those variants responsible for primarily DEE- 21(76.7 %); neuro-metabolic disorders- 3(18.6 %) and chromosomal deletions- 2(4.7 %). Of these patients, early-infantile epilepsy onset ≤ 6 months age was noted in 22(84.6 %). The DEE studied included Ohtahara syndrome associated with STXBP1 and SCN8A variants with yield of 50 % (2/4 tested); early myoclonic encephalopathy (no yield in 2); West syndrome with CDKL5, yield of 13.3 % (2/15 tested); epilepsy of infancy with migrating partial seizures due to CACNA1A and KCNT1 variants, yield of 67 % (2/3 tested); DEE-unclassified with KCNQ2, AP3B2, ZEB2, metabolic variants (SUOX, ALDH7A1, GLDC) and chromosome deletions (chr 1p36, chr2q24.3); yield of 32 % (8/25 tested). Patients with Dravet syndrome/Dravet-like phenotypes (N = 33) had variants in SCN1A (N = 10), SCN1B, CHD2; yield of 36.4 % (12/33 tested; 57.1 % from NGS). Eighteen patients with potential variants (SCN1A, SCN2A, SCN8A, KCNQ2, ALDH7A1 which also included VUS) could be offered targeted therapy. CONCLUSIONS: Our study confirms a good yield of genetic testing in neonatal and infantile-onset DEE provided robust phenotyping of infants is attempted with prognostic and therapeutic implications, particularly relevant to centres with resource constraints.

Development of novel pH-sensitive nanoparticle-based transdermal patch for management of rheumatoid arthritis.

Aim: To formulate and evaluate a pH-responsive nanoparticle (NP)-based patch for efficient transdermal delivery of flurbiprofen against rheumatoid arthritis. Materials & methods: Nanoprecipitation technique was used for preparation of NPs and central composite design was employed for optimization purposes. Optimized NPs were loaded into the transdermal patch by the solvent evaporation method. Results: Prepared NPs exhibited an average size of 69 nm, while NPs loaded onto the transdermal patch showed sustained release and high permeation through the skin. In in vivo studies, the prepared carrier system elucidated high therapeutic potential in both acute and chronic inflammatory models as evident from the results of behavioral, radiological, histopathological and antioxidant analyses. Conclusion: The flurbiprofen-loaded pH-sensitive NP-based transdermal patch has the potential to manage rheumatoid arthritis effectively.

1q42.12q42.2 Deletion in a Child with Midline Defects and Hypoplasia of the Corpus Callosum.

Chromosome 1q42.12q42.2 deletions are documented as "disease causing" and show overlapping phenotypes depending on the genes involved in the deletion. In this report, we detected a 5.8-Mb deletion encompassing the chromosome 1q42.12q42.2 region in a 4-year-old boy with hypoplastic corpus callosum, epilepsy, developmental delay, microcephaly, cataract, cleft palate, and skeletal changes. The deletion was de novo. Genotype-phenotype correlations suggest that the major features of 1q42.12q42.2 microdeletion were attributed to the genes with a high probability of loss-of-function intolerance score in this deletion, namely LBR, ENAH, ACBD3, LIN9, ITPKB, CDC42BPA, ARF1, TAF5L, GALNT2, SPRTN, and EGLN1 along with GNPAT.

Multi-gene testing in neurological disorders showed an improved diagnostic yield: data from over 1000 Indian patients.

BACKGROUND: Neurological disorders are clinically heterogeneous group of disorders and are major causes of disability and death. Several of these disorders are caused due to genetic aberration. A precise and confirmatory diagnosis in the patients in a timely manner is essential for appropriate therapeutic and management strategies. Due to the complexity of the clinical presentations across various neurological disorders, arriving at an accurate diagnosis remains a challenge. METHODS: We sequenced 1012 unrelated patients from India with suspected neurological disorders, using TruSight One panel. Genetic variations were identified using the Strand NGS software and interpreted using the StrandOmics platform. RESULTS: We were able to detect mutations in 197 genes in 405 (40%) cases and 178 mutations were novel. The highest diagnostic rate was observed among patients with muscular dystrophy (64%) followed by leukodystrophy and ataxia (43%, each). In our cohort, 26% of the patients who received definitive diagnosis were primarily referred with complex neurological phenotypes with no suggestive diagnosis. In terms of mutations types, 62.8% were truncating and in addition, 13.4% were structural variants, which are also likely to cause loss of function. CONCLUSION: In our study, we observed an improved performance of multi-gene panel testing, with an overall diagnostic yield of 40%. Furthermore, we show that NGS (next-generation sequencing)-based testing is comprehensive and can detect all types of variants including structural variants. It can be considered as a single-platform genetic test for neurological disorders that can provide a swift and definitive diagnosis in a cost-effective manner.

Antihyperalgesic Properties of Honokiol in Inflammatory Pain Models by Targeting of NF-κB and Nrf2 Signaling.

The present study investigates the possible anti-nociceptive effect of intraperitoneal (i.p.) honokiol: a phenolic compound originally isolated from Magnolia officinalis, in acute and chronic inflammatory pain models. Doses of 0.1, 5, and 10 mg/kg honokiol were administered in carrageenan induced pain and the dose (honokiol 10 mg/kg i.p.) with most significant response among behavioral tests was selected for further experiments. The i.p. administration of honokiol inhibits mechanical hyperalgesia, mechanical allodynia, and thermal hyperalgesia, without causing any apparent toxicity. To elucidate the effect of honokiol on various cytokines and antioxidant enzymes, quantitative real-time-PCR was performed to determine the expression levels of pro-inflammatory cytokines and antioxidant enzymes. It is demonstrated that honokiol significantly reduced the expression levels of tumor necrosis factor (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF). Similarly, honokiol was also found to potentiate the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), superoxide dismutase 2 (SOD2), and heme oxygenase-1 (HO-1) levels. Additionally, honokiol significantly reduced plasma nitrite levels as compared to complete Freund's adjuvant (CFA) induced group. X-ray analysis and hematoxylin and eosin (H&E) staining of inflamed and treated paws showed that honokiol reduced the inflammation with significantly less leukocyte infiltration and soft tissue inflammation. In order to explore the possible mechanism of action of honokiol, agonists [piroxicam (5 mg/kg), tramadol (50 mg/kg), and gabapentin (5 mg/kg) i.p.] as well as antagonists [naloxone (4 mg/kg), olanzapine (10 mg/kg), and flumazenil (0.2 mg/kg) i.p.] were used to study involvement of various receptors on the anti-nociceptive effect of honokiol. The potential side effects of honokiol on muscle activity were assessed. An adverse effect testing of honokiol by liver and renal functions were also carried out. The effect of oral honokiol was also assessed on gastrointestinal (GIT) mucosa. Our results demonstrate that honokiol has a significant anti-nociceptive activity through inhibition of anti-inflammatory mediators.

Efficacy of a single-dose regimen of inactivated whole-cell oral cholera vaccine: results from 2 years of follow-up of a randomised trial.

BACKGROUND: A single-dose regimen of inactivated whole-cell oral cholera vaccine (OCV) is attractive because it reduces logistical challenges for vaccination and could enable more people to be vaccinated. Previously, we reported the efficacy of a single dose of an OCV vaccine during the 6 months following dosing. Herein, we report the results of 2 years of follow-up. METHODS: In this placebo-controlled, double-blind trial done in Dhaka, Bangladesh, individuals aged 1 year or older with no history of receipt of OCV were randomly assigned to receive a single dose of inactivated OCV or oral placebo. The primary endpoint was a confirmed episode of non-bloody diarrhoea for which the onset was at least 7 days after dosing and a faecal culture was positive for Vibrio cholerae O1 or O139. Passive surveillance for diarrhoea was done in 13 hospitals or major clinics located in or near the study area for 2 years after the last administered dose. We assessed the protective efficacy of the OCV against culture-confirmed cholera occurring 7-730 days after dosing with both crude and multivariable per-protocol analyses. This trial is registered at ClinicalTrials.gov, number NCT02027207. FINDINGS: Between Jan 10, 2014, and Feb 4, 2014, 205 513 people were randomly assigned to receive either vaccine or placebo, of whom 204 700 (102 552 vaccine recipients and 102 148 placebo recipients) were included in the per-protocol analysis. 287 first episodes of cholera (109 among vaccine recipients and 178 among placebo recipients) were detected during the 2-year follow-up; 138 of these episodes (46 in vaccine recipients and 92 in placebo recipients) were associated with severe dehydration. The overall incidence rates of initial cholera episodes were 0·22 (95% CI 0·18 to 0·27) per 100 000 person-days in vaccine recipients versus 0·36 (0·31 to 0·42) per 100 000 person-days in placebo recipients (adjusted protective efficacy 39%, 95% CI 23 to 52). The overall incidence of severe cholera was 0·09 (0·07 to 0·12) per 100 000 person-days versus 0·19 (0·15 to 0·23; adjusted protective efficacy 50%, 29 to 65). Vaccine protective efficacy was 52% (8 to 75) against all cholera episodes and 71% (27 to 88) against severe cholera episodes in participants aged 5 years to younger than 15 years. For participants aged 15 years or older, vaccine protective efficacy was 59% (42 to 71) against all cholera episodes and 59% (35 to 74) against severe cholera. The protection in the older age groups was sustained throughout the 2-year follow-up. In participants younger than 5 years, the vaccine did not show protection against either all cholera episodes (protective efficacy -13%, -68 to 25) or severe cholera episodes (-44%, -220 to 35). INTERPRETATION: A single dose of the inactivated whole-cell OCV offered protection to older children and adults that was sustained for at least 2 years. The absence of protection of young children might reflect a lesser degree of pre-existing natural immunity in this age group. FUNDING: Bill & Melinda Gates Foundation to the International Vaccine Institute.

Screening of over 1000 Indian patients with breast and/or ovarian cancer with a multi-gene panel: prevalence of BRCA1/2 and non-BRCA mutations.

PURPOSE: Breast and/or ovarian cancers are among the most common cancers in women across the world. In the Indian population, the healthcare burden of breast and/or ovarian cancers has been steadily rising, thus stressing the need for early detection, surveillance, and disease management measures. However, the burden attributable to inherited mutations is not well characterized. METHODS: We sequenced 1010 unrelated patients and families from across India with an indication of breast and/or ovarian cancers, using the TruSight Cancer panel which includes 14 genes, strongly associated with risk of hereditary breast and/or ovarian cancers. Genetic variations were identified using the StrandNGS software and interpreted using the StrandOmics platform. RESULTS: We were able to detect mutations in 304 (30.1%) cases, of which, 56 mutations were novel. A majority (84.9%) of the mutations were detected in the BRCA1/2 genes as compared to non-BRCA genes (15.1%). When the cases were stratified on the basis of age at diagnosis and family history of cancer, the high rate of 75% of detection of hereditary variants was observed in patients whose age at diagnosis was below 40 years and had first-degree family member(s) affected by breast and/or ovarian cancers. Our findings indicate that in the Indian population, there is a high prevalence of mutations in the high-risk breast cancer genes: BRCA1, BRCA2, TP53, and PALB2. CONCLUSION: In India, socioeconomic inequality limiting access to treatment is a major factor towards increased cancer burden; therefore, incorporation of a cost-effective and comprehensive multi-gene test will be helpful in ensuring widespread implementation of genetic screening in the clinical practice for hereditary breast and/or ovarian cancers.

Mutation Spectrum of GNE Myopathy in the Indian Sub-Continent.

BACKGROUND: GNE myopathy is an adult onset recessive genetic disorder that affects distal muscles sparing the quadriceps. GNE gene mutations have been identified in GNE myopathy patients all over the world. Homozygosity is a common feature in GNE myopathy patients worldwide. OBJECTIVES: The major objective of this study was to investigate the mutation spectrum of GNE myopathy in India in relation to the population diversity in the country. MATERIALS AND METHODS: We have collated GNE mutation data of Indian GNE myopathy patients from published literature and from recently identified patients. We also used data of people of Indian subcontinent from 1000 genomes database, South Asian Genome database and Strand Life Science database to determine frequency of GNE mutations in the general population. RESULTS: A total of 67 GNE myopathy patients were studied, of whom 21% were homozygous for GNE variants, while the rest were compound heterozygous. Thirty-five different mutations in the GNE gene were recorded, of which 5 have not been reported earlier. The most frequent mutation was p.Val727Met (65%) found mainly in the heterozygous form. Another mutation, p.Ile618Thr was also common (16%) but was found mainly in patients from Rajasthan, while p.Val727Met was more widely distributed. The latter was also seen at a high frequency in general population of Indian subcontinent in all the databases. It was also present in Thailand but was absent in general population elsewhere in the world. CONCLUSION: p.Val727Met is likely to be a founder mutation of Indian subcontinent.

Genetic variants in post myocardial infarction patients presenting with electrical storm of unstable ventricular tachycardia.

Electrical storm (ES) is a life threatening clinical situation. Though a few clinical pointers exist, the occurrence of ES in a patient with remote myocardial infarction (MI) is generally unpredictable. Genetic markers for this entity have not been studied. In the present study, we carried out genetic screening in patients with remote myocardial infarction presenting with ES by next generation sequencing and identified 25 rare variants in 19 genes predominantly in RYR2, SCN5A, KCNJ11, KCNE1 and KCNH2, CACNA1B, CACNA1C, CACNA1D and desmosomal genes - DSP and DSG2 that could potentially be implicated in electrical storm. These genes have been previously reported to be associated with inherited syndromes of Sudden Cardiac Death. The present study suggests that the genetic architecture in patients with remote MI and ES of unstable ventricular tachycardia may be similar to that of Ion channelopathies. Identification of these variants may identify post MI patients who are predisposed to develop electrical storm and help in risk stratification.

Clinical and genetic analysis of Indian patients with NDP-related retinopathies.

PURPOSE: NDP-related retinopathies are a group of X-linked disorders characterized by degenerative and proliferative changes of the neuroretina, occasionally accompanied with varying degrees of mental retardation and sensorineural hearing loss. NDP is the predominant gene associated with NDP-related retinopathies. The purpose of this study was to report the clinical and genetic findings in three unrelated patients diagnosed with NDP-related retinopathies. METHODS: The patients underwent complete ophthalmic examination followed by genetic analyses. NDP gene was screened by direct sequencing approach. Targeted resequencing of several other ocular genes was carried out in patient samples that either indicated NDP gene deletion or tested negative for NDP mutation. Gene quantitation analysis was performed using real-time PCR. RESULTS: The whole NDP gene was deleted in patient I, while a missense NDP mutation, c.205T>C, was identified in patient II, and both had classical Norrie disease ocular phenotype (with no other systemic defects). Patient III who was diagnosed with familial exudative vitreoretinopathy did not show any mutation in the known candidate genes as well as in other ocular genes tested. CONCLUSIONS: The patient with whole NDP gene deletion did not exhibit any apparent extraocular defects (like mental retardation or sensorineural hearing loss) during his first decade of life, and this is considered to be a notable finding. Our study also provides evidence emphasizing the need for genetic testing which could eliminate ambiguities in clinical diagnosis and detect carrier status, thereby aiding the patient and family members during genetic counseling.