A Rare Case of Mosaic 3pter and 5pter Deletion-Duplication with Autism Spectrum Disorder and Dyskinesia.

Introduction: There is evidence that neurodevelopmental disorders are associated with chromosomal abnormalities. Current genetic testing can clinch an exact diagnosis in 20-25% of such cases. Case Description. A 3 years and 11 months old boy with global developmental delay had repetitive behaviors and hyperkinetic movements. He was stunted and underweight. He had ataxia, limb dyskinesia, triangular face, microcephaly, upward slanting palpebral fissure, hypertelorism, retrognathia, posteriorly rotated ears, long philtrum, thin lips, broad nasal tip, polydactyly, tappering fingers, and decreased tone in the upper and lower limbs with normal deep tendon reflexes. Magnetic resonance imaging of the brain, ultrasound of the abdomen, and ophthalmological evaluation were normal. Brain evoked response auditory revealed bilateral moderate hearing loss. He fulfilled the Diagnostic Statistical Manual 5 criteria for autism. In the Vineland Social Maturity Scale, his score indicated a severe delay in social functioning. His genetic evaluation included karyotyping, fluorescence in situ hybridization (FISH), and chromosomal microarray analysis (CMA). The karyotype report from high-resolution lymphocyte cultures was mos 46, XY, der(3)t(3; 5)(p26; p15.3)[50]/46, XY,der(5) t(3;5) (p26;p15.3)[50].ish. His karyotype report showed a very rare and abnormal mosaic pattern with two cell lines (50% each). Cell-line#1: 3pter deletion with 5pter duplication (3pter-/5pter+) and cell-line#2: 3pter duplication with 5pter deletion (3pter+/5pter-) derived from a de novo reciprocal translocation t(3; 5)(p26; p15.3) which was confirmed by FISH. The chromosomal microarray analysis report was normal. The two cell lines (50% each) seem to have balanced out at the whole genome level. Occupational, sensory integration, and behavior modification therapy were initiated for his autistic features, and anticholinergic trihexiphenidyl was prescribed for hyperkinetic movements. Conclusion: This case highlights a rare genetic finding and the need for timely genetic testing in a child with dysmorphism and autism with movement disorder to enable appropriate management and genetic counselling.

Prenatal Diagnosis by Chromosome Microarray Analysis, An Indian Experience.

BACKGROUND: Karyotyping has been the gold standard for prenatal chromosome analysis. The resolution should be higher by chromosome microarray analysis (CMA). The challenge lies in recognizing benign and pathogenic or clinically significant copy number variations (pCNV) and variations of unknown significance (VOUS). The aim was to evaluate the diagnostic yield and clinical utility of CMA, to stratify the CMA results in various prenatal referral groups and to accumulate Indian data of pCNVs and VOUS for further interpretation to assist defined genetic counseling. METHODS: Karyotyping and CMA were performed on consecutive referrals of 370 prenatal samples of amniotic fluid (n = 274) and chorionic villi (n = 96) from Indian pregnant women with high maternal age (n = 23), biochemical screen positive (n = 61), previous child abnormal (n = 59), abnormal fetal ultrasound (n = 205) and heterozygous parents (n = 22). RESULTS AND CONCLUSION: The overall diagnostic yield of abnormal results was 5.40% by karyotyping and 9.18% by CMA. The highest percentage of pCNVs were found in the group with abnormal fetal ultrasound (5.40%) as compared to other groups, such as women with high maternal age (0.81%), biochemical screen positive (0.54%), previous abnormal offspring (0.81%) or heterozygous parents group (1.62%). Therefore, all women with abnormal fetal ultrasound must undergo CMA test for genotype-phenotype correlation. CMA detects known and rare deletion/duplication syndromes and characterizes marker chromosomes. Accumulation of CNV data will form an Indian Repository and also help to resolve the uncertainty of VOUS. Pretest and posttest genetic counseling is essential to convey benefits and limitations of CMA and help the patients to take informed decisions.

Severe Polyhydramnios with Consistent Fetal Full Bladder: A Novel Sign of Antenatal Bartter's Disease.

Bartter's disease, an inherited renal tubular disorder is due to a defect in ion transport across the ascending limb of the loop of Henle leading to failure of the ability of kidneys to concentrate urine and hence polyuria. We present three fetuses of mothers with severe polyhydramnios with normal maternal blood sugar profile, routine Toxoplasma, Rubella, Cytomegalovirus, Herpes (TORCH) serology. The ultrasound showed no structural anomaly in the fetus, but consistent overdistended bladder with severe polyhydramnios was observed without any evidence of obstructive uropathy. The biochemical test on amniotic fluid was suggestive of Bartter's disease in case 1 and borderline in case 2, and next-generation sequencing confirmed a mutation of KCNJ1 associated with Bartter's disease Type II in case 1 and a mutation in SLC21A1 in case 2. Amniotic fluid biochemistry was inconclusive in case 3. A consistent full bladder with severe polyhydramnios with onset around 24 to 25 weeks was a novel finding which was observed due to fetal polyuria and can be used as a clue to investigate cases with severe polyhydramnios with no structural anomaly. Antenatal diagnosis will help in the proper management of child and genetic counseling for the next pregnancy.

Genetic Testing in Pediatric Ophthalmology.

The authors review the utility of genetic testing in ophthalmic disorders - precise diagnosis, accurate prognosis, genetic counseling, prenatal diagnosis, and entry into gene-specific therapeutic trials. The prerequisites for a successful outcome of a genetic test are an accurate clinical diagnosis, a careful family history that guides which genes to study, and genetic counseling (both pre-test and post-test). The common eye disorders for which genetic testing is commonly requested are briefly discussed - anophthalmia, microphthalmia, coloboma, anterior segment dysgenesis, corneal dystrophies, cataracts, optic atrophy, congenital glaucoma, congenital amaurosis, retinitis pigmentosa, color blindness, juvenile retinoshisis, retinoblastoma etc. A protocol for genetic testing is presented. If specific mutations in a gene are common, they should form the first tier test, as the mutations in Leber hereditary optic neuropathy. If mutations in one gene are likely, sequencing of that gene should be carried out, e.g. GALT gene in galactosemia, RS1 gene in retinoshisis. Disorders with genetic heterogeneity require multi-gene panel tests, and if these show no abnormality, then deletion / duplication or microarray studies are recommended, followed in sequence by clinical exome (5000 to 6000 genes), full exome (about 20,000 genes or whole genome studies (includes all introns). It is fortunate that most genetic tests in ophthalmology are available in India, including gene panel and whole exome/genome sequencing tests.

Association of ZEB1 and TCF4 rs613872 changes with late onset Fuchs endothelial corneal dystrophy in patients from northern India.

PURPOSE: Fuchs endothelial corneal dystrophy (FECD) results in loss of vision associated with progressive corneal edema and loss of corneal transparency. The aim of the study was to evaluate changes in ZEB1, COL8A2, SLC4A11, and TCF4 rs613872 and correlate them with clinical findings. METHODS: Eighty-two patients with clinically diagnosed FECD and 143 controls were recruited during the period 2007-2012. Clinical details, pedigree information up to three generations, and 5 ml of blood samples were collected. Histopathological and transmission electron microscopy studies were performed on host corneal buttons from patients who underwent keratoplasty. Genomic DNA from blood was processed for PCR amplification followed by direct sequencing to screen genetic changes in the candidate genes. The pathogenic nature of the genetic variants was assessed using Sorting Intolerant From Tolerant (SIFT) and MutationTaster. RESULTS: The mean age at the onset of symptoms was 59.14±1.41years, the male to female ratio was 1:1.5, and the mean specular count (endothelial cell density) was 1629±93.62 cells/mm(2) with a mean central corneal thickness (CCT) of 617.30±15.73 µm. ZEB1 showed a novel variant IVS2+276 C/T in 14% of the cases, a novel nonsense p.Leu947stop mutation in one patient, two novel missense mutations (p.Glu733Lys, p.Ala818Val) in one patient each, and one novel synonymous variation (p.Ser234Ser) in two patients. Reported mutation p.Gln840Pro and five polymorphisms were also identified. The TCF4 single nucleotide polymorphism (SNP) rs613872 was significantly higher in patients with FECD. CONCLUSIONS: This is the first report of genetic variations in ZEB1 and TCF4 SNP rs613872 in patients with FECD from northern India that suggests a possible role in disease pathogenesis and the regulation of endothelial cell density.

Systemic attenuation of the TGF-ß pathway by a single drug simultaneously rejuvenates hippocampal neurogenesis and myogenesis in the same old mammal.

Stem cell function declines with age largely due to the biochemical imbalances in their tissue niches, and this work demonstrates that aging imposes an elevation in transforming growth factor ß (TGF-ß) signaling in the neurogenic niche of the hippocampus, analogous to the previously demonstrated changes in the myogenic niche of skeletal muscle with age. Exploring the hypothesis that youthful calibration of key signaling pathways may enhance regeneration of multiple old tissues, we found that systemically attenuating TGF-ß signaling with a single drug simultaneously enhanced neurogenesis and muscle regeneration in the same old mice, findings further substantiated via genetic perturbations. At the levels of cellular mechanism, our results establish that the age-specific increase in TGF-ß1 in the stem cell niches of aged hippocampus involves microglia and that such an increase is pro-inflammatory both in brain and muscle, as assayed by the elevated expression of ß2 microglobulin (B2M), a component of MHC class I molecules. These findings suggest that at high levels typical of aged tissues, TGF-ß1 promotes inflammation instead of its canonical role in attenuating immune responses. In agreement with this conclusion, inhibition of TGF-ß1 signaling normalized B2M to young levels in both studied tissues.

Prospective Case-Control Study to Evaluate the Role of Glutathione S Transferases (GSTT1 and GSTM1) Gene Deletion in Breast Carcinoma and Its Prognostic Significance.

Breast cancer is the most common cause of cancer death in women with the incidence rising in young women. GST gene polymorphisms are significant because of their role in the detoxification of both environmental carcinogens and also cytotoxic drugs used in therapy for breast cancer. The present study has been designed to identify the role of polymorphisms in GSTT1 and GSTM1 genes in the risk of development of breast cancer, in the prognostication of breast cancer, and in the prediction of response towards chemotherapy. Ninety-nine patients with breast cancer and 100 healthy controls with no history of cancer were taken from blood donors after informed consent. Epidemiological and clinical data was collected from participants and 5 ml of peripheral venous blood was collected for genotype analysis. Null genotype of GSTT1 was detected in 51.04 % of the controls in comparison to 20.2 % of patients with carcinoma breast, which was found to be statistically significant (OR 4.18; 95 % CI 2.01-8.75; P = 0.0001). GSTM1 gene deletion was also significantly more common among controls (60 %) than in patients with breast cancer (33 %) (OR 4.57; 95 % CI 2.20-9.51; P = 0.0001). Tumors more than 5 cm in size had greater tendency for GSTM1 gene expression (P value = 0.019), but other clinicopathological parameters did not show any correlation. GSTT1 and GSTM1 genes status did not show any association with response to chemotherapy. The results indicated the null genotype of both GSTT1 and GSTM1 to be protective for the development of carcinoma breast. None of the known etiological factors have any correlation with GSTT1 and GSTM1 gene deletion. Patients with small tumor size expressed GSTM1 gene deletion. Other tumor characteristics and clinicopathological parameters did not have any correlation with gene deletion.

Age dependent increase in the levels of osteopontin inhibits skeletal muscle regeneration.

Skeletal muscle regeneration following injury is accompanied by rapid infiltration of macrophages, which play a positive role in muscle repair. Increased chronic inflammation inhibits the regeneration of dystrophic muscle, but the properties of inflammatory cells are not well understood in the context of normal muscle aging. This work uncovers pronounced age-specific changes in the expression of osteopontin (OPN) in CD11b+ macrophages present in the injured old muscle as well as in the blood serum of old injured mice and in the basement membrane surrounding old injured muscle fibers. Furthermore, young CD11b+ macrophages enhance regenerative capacity of old muscle stem cells even when old myofibers and old sera are present; and neutralization of OPN similarly rejuvenates the myogenic responses of old satellite cells in vitro and notably, in vivo. This study highlights potential mechanisms by which age related inflammatory responses become counter-productive for muscle regeneration and suggests new strategies for enhancing muscle repair in the old.

Molecular genetic analysis of macular corneal dystrophy patients from North India.

PURPOSE: To identify underlying genetic defects in the carbohydrate sulfotransferase-6 (CHST6) gene in North Indian patients with macular corneal dystrophy (MCD). METHODS: 30 clinically diagnosed MCD patients from 21 families and 50 healthy normal controls were recruited in the study. Detailed clinical evaluation in the patients was undertaken followed by histopathology and ultrastructural studies in corneal tissues. DNA from blood samples was amplified for the CHST6 coding and upstream region followed by direct sequencing and in silico analysis. RESULTS: We identified pathogenic mutations in 17 patients from 11 families. Of these 4 were novel (p.Ser54Tyr, p.Gln58Arg, p.Leu59His and p.Leu293Phe), 2 were previously reported (Arg93His and Glu274Lys) homozygous, 1 heterozygous stop codon (p.Trp123X) and 2 compound heterozygous (p.Arg93His + p.Arg97Pro; p.Leu22Arg + p.Gln58X) mutations. A missense single-nucleotide polymorphism was also identified in 11 patients. The novel mutations were conserved as shown by in silico analysis. Thirteen patients did not show any pathogenic CHST6 changes. CONCLUSIONS: This is the first report on molecular analysis of MCD in North Indian patients. All cases could not be explained by mutations in CHST6, suggesting that MCD may result from other changes in the regulatory elements of CHST6 or from genetic heterogeneity.

Inhibitors of tyrosine phosphatases and apoptosis reprogram lineage-marked differentiated muscle to myogenic progenitor cells.

Muscle regeneration declines with aging and myopathies, and reprogramming of differentiated muscle cells to their progenitors can serve as a robust source of therapeutic cells. Here, we used the Cre-Lox method to specifically label postmitotic primary multinucleated myotubes and then utilized small molecule inhibitors of tyrosine phosphatases and apoptosis to dedifferentiate these myotubes into proliferating myogenic cells, without gene overexpression. The reprogrammed, fusion competent, muscle precursor cells contributed to muscle regeneration in vitro and in vivo and were unequivocally distinguished from reactivated reserve cells because of the lineage marking method. The small molecule inhibitors downregulated cell cycle inhibitors and chromatin remodeling factors known to promote and maintain the cell fate of myotubes, facilitating cell fate reversal. Our findings enhance understanding of cell-fate determination and create novel therapeutic approaches for improved muscle repair.

Familial segregation of a VSX1 mutation adds a new dimension to its role in the causation of keratoconus.

PURPOSE: To look for segregation of Visual System Homeobox 1 (VSX1) mutations in family members of a patient with keratoconus. METHODS: Our initial molecular genetic studies conducted to identify the role of VSX1 in the causation of keratoconus had identified a novel mutation in one patient. He later presented to the clinic affected with vernal kerato conjunctivitis (VKC) accompanied by his brother, also similarly affected. All the family members were called and detailed clinical evaluations were undertaken. DNA from the blood samples of all family members was amplified using primers specific for VSX1 and analyzed by direct sequencing to look for segregation of the mutation in the family members. Protein modeling studies were done to assess the effect of the mutation on protein structure and function. RESULTS: Clinical examination of the family revealed bilateral keratoconus and VKC in the proband and his brother. One of his sisters had VKC without keratoconus and his parents and another sister were normal. Molecular analysis identified the VSX1 mutation Q175H in the affected brother and in the mother who had neither VKC nor keratoconus but only the VSX1 Q175H sequence change. CONCLUSIONS: The VSX1 Q175H mutation may be a pathogenic variant with incomplete penetrance. Protein modeling studies show that the mutation affects the DNA binding properties of the protein. This VSX1 variant exhibiting low penetrance may require the presence of some modifier genes or environmental factors for disease presentation. VSX1 may have an important role in the pathogenesis of keratoconus which needs further investigation.

A novel TGFBI phenotype with amyloid deposits and Arg124Leu mutation.

AIM: To report a unique transforming-growth-factor-ß-induced (TGFBI) gene phenotype with Arg124Leu mutation in an Indian family. METHODS: A family with 5 affected members presented to our hospital and were clinically diagnosed as suffering from Bowman layer dystrophy after examination. Peripheral blood samples were collected in EDTA from all for genomic DNA isolation. Keratoplasty was performed in 2 patients followed by histopathological evaluation of the cornea. DNA was subjected to PCR amplification of TGFBI and tumor-associated calcium signal transducer 2 (TACSTD2) genes followed by direct sequencing of all coding exons to identify the causative mutations. RESULTS: Slitlamp examination of the cornea revealed superficial reticular opacities with diffuse anterior stromal haze suggestive of Bowman layer dystrophy but histopathological examination revealed the presence of both hyaline and amyloid deposits in the cornea. TGFBI sequencing revealed a heterozygous mutation, Arg124Leu (c.418 G→T) in all the affected members while TACSTD2 did not show any changes. CONCLUSIONS: Molecular analysis established the diagnosis of a novel TGFBI variant with Arg124Leu mutation. The presence of lattice- like lines clinically and histopathological demonstration of both amyloid and hyaline deposits with the occurrence of Arg124Leu mutation in all the affected family members are an unusual phenomenon and are here described for the first time.

Identification of novel SRY mutations and SF1 (NR5A1) changes in patients with pure gonadal dysgenesis and 46,XY karyotype.

Primary amenorrhea due to 46,XY disorders of sexual development (DSD) is complex with the involvement of several genes. Karyotyping of such patients is important as they may develop dysgerminoma and molecular analysis is important to identify the underlying mechanism and explore the cascade of events occurring during sexual development. The present study was undertaken for the genetic analysis in seven patients from five families presenting with primary amenorrhea and diagnosed with pure gonadal dysgenesis. Karyotyping was done and the patients were screened for underlying changes in SRY, desert hedgehog (DHH), DAX1 (NR0B1) and SF1 (NR5A1) genes, mutations in which are implicated in DSD. All the patients had 46,XY karyotype and two novel SRY mutations were found. In Family 1 (Patient S1.1) a missense mutation c.294G>A was seen, which results in a stop codon at the corresponding amino acid (Trp98X) and in Family 2 (Patients S2.1, S2.2 and S2.3), a missense mutation c.334G>A (Glu112Leu) was identified in all affected sisters. Both mutations were seen to occur in the conserved high mobility group box of SRY gene. One heterozygous change c.427G>A resulting in Glu143Lys in DHH gene in one patient and two heterozygous changes in the intronic region of SF1 (NR5A1) gene (c.244+80G>A+ c.1068-20C>T) in another patient were noted. One individual did not show changes in any of the genes analyzed. These results reiterate the importance of SRY and others, such as SF1 (NR5A1) and DHH, that are involved in the cascade of events leading to sex determination and also their role in sex reversal.

TGFBI mutation screening and genotype-phenotype correlation in north Indian patients with corneal dystrophies.

PURPOSE: To screen a cohort of corneal dystrophy patients from North India for mutations in the transforming growth factor beta induced (TGFBI) gene, to correlate genotypes to phenotypes, to describe structural implications of various mutations on protein function, and to discuss the implications for diagnosis. METHODS: Eighty affected individuals from 61 unrelated families, who were diagnosed with autosomal dominant granular and/or lattice corneal dystrophy, were recruited for the study. Detailed clinical evaluation was undertaken for these patients to establish their corneal phenotypes. Genomic DNA was isolated from peripheral blood samples and all exons of TGFBI were screened for mutations by polymerase chain reaction (PCR) and direct DNA sequencing. Protein molecular dynamics (MD) simulations were performed for the mutations detected to assess the changes in protein structure. RESULTS: The most common mutations seen were Arg555Trp and Arg124Cys. Two novel mutations, Ser516Arg (c.DNA1548C>G), with a phenotype similar to granular corneal dystrophy I (GCDI), and Leu559Val (c.DNA1675T>G), with an atypical phenotype closely resembling epithelial basement membrane dystrophy/map dot fingerprint dystrophy, were identified. Protein modeling studies involving wild type and mutant protein indicated that the Leu559Val is a destabilizing mutation and that Ser516Arg could adversely affect the specific binding of Fas1 domain 4 with other proteins. In addition, two single-nucleotide polymorphisms, rs4669 and rs11331170, were also identified. Mutations were not identified in 8 affected individuals, 6 of whom were diagnosed with bowman layer dystrophy and 2 with lattice corneal dystrophy. CONCLUSIONS: This is the first comprehensive report of TGFBI mutations covering a large part of North India. Identification of novel mutations, the presence of phenotypic variability, and the genetic heterogeneity seen in our cases stress the need for mandatory screening of TGFBI for precise diagnosis and classification of corneal dystrophies.

Identification and characterization of a novel TACSTD2 mutation in gelatinous drop-like corneal dystrophy.

PURPOSE: To study the clinical, histological, in vivo confocal microscopic, and molecular profile in a family with gelatinous drop-like corneal dystrophy (GDLD) from north India. METHODS: Two siblings from a consanguineous family presented with clinical features analogous to GDLD. Detailed clinical evaluations were performed for all the available affected and unaffected members of this family. In vivo confocal microscopy and histology was done wherever necessary. DNA isolated from peripheral blood samples was subjected to polymerase chain reaction (PCR) followed by direct sequencing to detect mutations in the tumor-associated calcium signal transducer 2 (TACSTD2) gene. Protein modeling studies were done to asses the effect of the mutation on the protein structure. RESULTS: The diagnosis of GDLD was established in the patient and the affected sibling on slit-lamp examinations, which revealed mulberry-like opacities in the subepithelium and anterior stroma that were confirmed on histopathology. The findings of the in vivo confocal microscopy were consistent with those reported in previous reports. Sequencing TACSTD2 revealed a novel homozygous missense mutation c.356G>A, leading to amino acid substitution C119Y in the two affected siblings. The mutation was found to be pathogenic on Sorting Intolerant From Tolerant (SIFT) analysis and was not found in normal controls and unaffected individuals of the family. A synonymous, previously reported, single nucleotide polymorphism (SNP; rs13267) was also seen in all the individuals of the family. Protein modeling studies involving wild-type and mutant protein indicated an exposed cysteine residue in the mutant protein. CONCLUSIONS: A novel TACSTD2 C119Y mutation leading to an amino acid substitution was identified in two affected siblings of a family. Protein modeling studies revealed an exposed cysteine residue, which might cause interchain disulfide bond formation and protein aggregation leading to disturbed cell junctions of the corneal epithelium.

An unusual association of hypospadias with partial deletion of chromosome 1q.

OBJECTIVE: To report an unusual finding of chromosome 1q deletion in a man with failed multiple hypospadias repair. DESIGN: Case report and discussion. SETTING: An academic tertiary care hospital. PATIENT(S): A 32-year-old man with failed multiple hypospadias repair. INTERVENTION(S): Clinical, hormonal, cytogenetic evaluation, fluorescent in situ hybridization (FISH), and ultrasonography. MAIN OUTCOME MEASURE(S): Serum gonadotropin and testosterone levels, and karyotype showing structural abnormality of long arm of chromosome 1. RESULT(S): Ultrasonography showed the absence of the left testis and a hypoechoic right testis. Serum luteinizing hormone and follicular stimulating hormone levels were raised, but testosterone and prolactin levels were within the normal range for adult men. Karyotype analysis revealed an interstitial deletion of the long arm of chromosome 1, which was confirmed by FISH. CONCLUSION(S): Chromosome 1 may harbor a critical domain that is essential for male fertility.

Spinal myxopapillary ependymoma with Down syndrome: exploring an unusual association.

SUMMARY: In patients with Down syndrome, cancers like leukemia and testicular tumors are frequent, but association with central nervous system tumors is rare. Only 1 case of ependymoma has been observed as an incidental autopsy finding in a 19-week-old female fetus. We herein report the second case of ependymoma and the fifth case of spinal tumor occurring in association with Down syndrome. We have also attempted to elucidate the various mechanisms of tumorigenesis implicated in this multiple malformation syndrome. A 13-year-old girl with Down syndrome presented with progressively increasing paraparesis and neurogenic bladder. Magnetic resonance imaging of dorsolumbar spine revealed an intramedullary mass (L1 to L5 level). The patient underwent near total excision of tumor with postoperative histopathology showing myxopapillary ependymoma. Karyotyping showed classic Down syndrome with trisomy 21. Postoperative irradiation (45 Gy in 25 fractions over 5 wk followed by boost up to 55 Gy) was subsequently delivered. One year after the completion of the tumor-directed therapy, the patient is in radiologic complete remission, with improved power in both lower limbs. Association of ependymoma with Down syndrome is a rarity, which at best, can be explained as a chance phenomenon.

Congenital hereditary endothelial dystrophy - mutation analysis of SLC4A11 and genotype-phenotype correlation in a North Indian patient cohort.

PURPOSE: To identify the solute carrier family 4 (sodium borate cotransporter) member 11 (SLC4A11) mutation spectrum and to perform genotype-phenotype correlations in autosomal recessive Congenital Hereditary Endothelial Dystrophy (CHED2) in North Indian patients. METHODS: Twenty-five patients from twenty families clinically diagnosed with autosomal recessive CHED2 were recruited for the study. Clinical parameters such as age at onset, presentation, and pre- and post-operative visual acuities were recorded. Corneal buttons of patients undergoing keratoplasty were analyzed for histopathologic and ultrastructural confirmation. All the affected individuals and 50 unrelated population matched normal controls were screened for underlying sequence changes. Genomic DNA was isolated from peripheral blood samples and all the exons and the 5'-upstream region of the SLC4A11 gene were screened for mutations by direct DNA sequencing. RESULTS: A high degree of consanguinity (9 out of 20 families) was noted. Corneal haze was reported to be present since birth or shortly thereafter in all affected patients. Histology and electron microscopy studies revealed increased thickness of Descemet's membrane, especially of the non-banded zone. Molecular studies revealed one novel homozygous in-frame deletion mutation in two affected siblings from one family and three other previously reported homozygous mutations in 12 patients from 9 families. Mutations were not identified in 11 patients from 11 families. High interfamilial and intrafamilial phenotypic variability was seen among the cohort of patients. CONCLUSIONS: This is the first report on the mutation spectrum and genotype-phenotype correlation in CHED2 patients from North India. The present study detected one novel and three reported changes, adding to the repertoire of mutations in SLC4A11, and recorded a high degree of genetic heterogeneity in CHED2.

A novel VSX1 mutation identified in an individual with keratoconus in India.

PURPOSE: To evaluate the possible role of the VSX1 gene in a group of patients from the Indian subcontinent with keratoconus. METHODS: Molecular analysis of 66 patients with a diagnosis of keratoconus, based on clinical examination and corneal topography, was carried out. DNA extraction from peripheral blood followed by Polymerase Chain Reaction (PCR) amplification of the VSX1 gene was performed. The entire coding region and the exon-intron junctions of the VSX1 gene were analyzed by direct sequencing. RESULTS: A novel change at c.525G>C, replacing amino acid glutamine at position 175 with histidine, was found in one affected individual. One of the previously reported SNPs (rs12480307) was found with equal frequency in both patients and controls. CONCLUSIONS: This is the first report from the Indian subcontinent exploring the role of VSX1 in the causation of keratoconus. One novel mutation (Q175H) predicted to be a potentially damaging change was seen in an affected individual; this substantiates the importance of this gene but its precise role in disease causation needs further investigation.

Clinical and genetic profile of Avellino corneal dystrophy in 2 families from north India.

OBJECTIVE: To report Avellino corneal dystrophy and underlying R124H mutation in 2 families of Indian origin. METHODS: Peripheral blood was collected in EDTA for genomic DNA isolation from leukocytes of all affected and unaffected individuals. Amplification of transforming growth factor beta-induced gene (TGFBI) using polymerase chain reaction followed by direct sequencing was carried out to determine the mutations underlying the disorder. A detailed clinical evaluation was undertaken to establish a genotype-phenotype correlation. RESULTS: R124H mutation resulting from a missense heterozygous substitution of G to A at nucleotide 418 of TGFBI was detected in all affected members of the 2 families. The affected individuals were clinically diagnosed as having granular corneal dystrophy. Histopathological examination was not done because no surgical intervention was undertaken. CONCLUSIONS: To our knowledge, this is the first report of Avellino corneal dystrophy from India clinically diagnosed as granular corneal dystrophy, emphasizing that TGFBI screening is essential for the accurate diagnosis and classification of corneal dystrophies. CLINICAL RELEVANCE: Molecular genetics is a useful tool for accurate diagnosis and classification of corneal dystrophies. All autosomal dominant stromal dystrophies should be screened for underlying mutations in TGFBI because the clinical and phenotypic appearance is variable.