A biallelic variant in POLR2C is associated with congenital hearing loss and male infertility: Case report.

BACKGROUND: DNA-directed RNA polymerase II subunit 3 (RPB3) is the third largest subunit of RNA polymerase II and is encoded by the POLR2C (OMIM:180663). A large Iranian family with congenital hearing loss and infertility is described here with genetic and clinical characterizations of five male patients. METHODS: After doing clinical examinations, the proband was subjected to karyotyping and GJB2/6 sequencing to rule out the most evident chromosomal and gene abnormalities for male infertility and hearing loss, respectively. A custom-designed next-generation sequencing panel was also used to detect mutations in deafness-related genes. Finally, to reveal the underlying molecular cause(s) justifying hearing loss and male infertility, five male patients and 2 healthy male controls within the family were subjected to paired-end whole-exome sequencing (WES). Linkage analysis was also performed based on the data. RESULTS: All male patients showed prelingual sensorineural hearing loss and also decreased sperm motility. Linkage analysis determined 16q21 as the most susceptible locus in which a missense variant in exon 7 of POLR2C-NM_032940.3:c.545T>C;p.(Val182Ala)-was identified as a 'likely pathogenic' variant co-segregated with phenotypes. CONCLUSIONS: Using segregation and in silico analyses, for the first time, we suggested that the NM_032940.3:c.545T>C; p.(Val182Ala) in POLR2C is associated with hearing loss and male infertility.

Reporting a novel growth hormone receptor gene variant in an Iranian consanguineous pedigree with Laron syndrome: a case report.

BACKGROUND: Human growth hormone (hGH) plays a crucial role in growth by binding to growth hormone receptor (GHR) in target cells. Binding of GH molecules to their cognate receptors triggers downstream signaling pathways leading to the transcription of several genes, including insulin-like growth factor (IGF)-1. Pathogenic variants in the GHR gene can result in structural and functional defects in the GHR protein, leading to Laron Syndrome (LS) with the primary clinical manifestation of short stature. So far, around 100 GHR variants have been reported, mostly biallelic, as causing LS. CASE PRESENTATION: We report on three siblings from an Iranian consanguineous family who presented with dwarfism. Whole-exome sequencing (WES) was performed on the proband, revealing a novel homozygous missense variant in the GHR gene (NM_000163.5; c.610 T > A, p.(Trp204Arg)) classified as a likely pathogenic variant according to the recommendation of the American College of Medical Genetics (ACMG). Co-segregation analysis was investigated using Sanger sequencing. CONCLUSIONS: To date, approximately 400-500 LS cases with GHR biallelic variants, out of them 10 patients originating from Iran, have been described in the literature. Given the high rate of consanguineous marriages in the Iranian population, the frequency of LS is expected to be higher, which might be explained by undiagnosed cases. Early diagnosis of LS is very important, as treatment is available for this condition.

Expanding phenotype heterogeneity of NARS2 by presenting subdural hematoma and parenchymal hemorrhage.

BACKGROUND: NARS2 encodes mitochondrial Asparaginyl-tRNA Synthetase 2, which catalyzes the aminoacylation of tRNA-Asn in the mitochondria. To date, 24 variants have been reported in NARS2 gene in 35 patients. The phenotypic variability of NARS2-associated disorder is broad, ranging from neurodevelopmental disorders to hearing loss. In this study, we report some novel imaging findings in an Iranian patient suffering from epileptic encephalopathy, caused by a previously reported variant, c.500A > G; p.(His167Arg), in NARS2. METHODS: The spectrum of clinical manifestations of two Iranian patients was investigated and genetic analysis was performed by Whole-exome sequencing (WES). Additionally, we also reviewed the literature and summarized the phenotypes of previously reported patients with variants in the NARS2 gene. RESULTS: Here, we present the phenotypic and genetic features of 2 unrelated Iranian infants presented with neurodevelopmental delay, seizures, hearing impairment, feeding problems, elevated serum lactate levels in addition to subdural hematoma and cerebral parenchymal hemorrhage in the brain magnetic resonance imaging (MRI) of one of the patients. Genetic analysis revealed a biallelic missense variant in NARS2: c.500A > G; p.(His167Arg). We described the subdural hematoma and cerebral parenchymal hemorrhage of the brain for the first time. CONCLUSIONS: Our study provides new clinical findings, subdural hematoma, and parenchymal hemorrhage, in NARS2-related disorders. Our findings along with previous studies provide more evidence of the clinical presentation of the disease caused by pathogenic variants in NARS2. Expanding the clinical spectrum increases the diagnostic rate of molecular testing and improves the quality of counseling for at-risk couples.

Compound Heterozygous Mutations in PNKP Gene in an Iranian Child with Microcephaly, Seizures, and Developmental Delay.

BACKGROUND: Pathogenic variants within polynucleotide kinase 3'phosphatase (PNKP) gene cause microcephaly, seizures, and developmental delay (MCSZ) and ataxia-oculomotor apraxia type 4 (AOA4) disorders due to unrepaired DNA lesions. METHODS: Whole exome sequencing was performed on a child with microcephaly, seizures, developmental delay, callosal dysgenesis on MRI, intellectual disability, speech disorder, hyperactivity, and ataxic gait. RESULTS: Two heterozygous mutations in the PKNP gene, a novel intronic frameshift variant c.1298 + 33_1299-24del and a previously reported duplication, c.1253_1269dup; p.Thr424Glyfs*49 in exon 14 were identified. Both of these mutations affect the DNA kinase domain of PKNP. CONCLUSIONS: Our finding along with previous studies provide more evidence of the clinical heterogeneity of diseases caused by mutations in PNKP which makes its clinical diagnosis difficult and highlights the importance of genetic testing to unravel the cause of these diseases.

Identification of novel variants in Iranian consanguineous pedigrees with nonsyndromic hearing loss by next-generation sequencing.

BACKGROUND: The extremely high genetic heterogeneity of hearing loss due to diverse group of genes encoding proteins required for development, function, and maintenance of the complex auditory system makes the genetic diagnosis of this disease challenging. Up to now, 121 different genes have been identified for nonsyndromic hearing loss (NSHL), of which 76 genes are responsible for the most common forms of NSHL, autosomal recessive nonsyndromic hearing loss (ARNSHL). METHODS: After excluding mutations in the most common ARNSHL gene, GJB2, by Sanger sequencing, genetic screening for a panel of genes responsible for hereditary hearing impairment performed in 9 individuals with ARNSHL from unrelated Iranian consanguineous pedigrees. RESULTS: One compound heterozygote and eight homozygote variants, of which five are novel, were identified: CDH23:p.(Glu1970Lys), and p.(Ala1072Asp), GIPC3:p.(Asn82Ser), and (p.Thr41Lys), MYO7A:p.[Phe456Phe]; p.[Met708Val], and p.(Gly163Arg), TECTA:p.(Leu17Leufs*19), OTOF:c.1392+1G>A, and TRIOBP:p.(Arg1068*). Sanger sequencing confirmed the segregation of the variants with the disease in each family. CONCLUSION: Finding more variants and expanding the spectrum of hearing impairment mutations can increase the diagnostic value of molecular testing in the screening of patients and can improve counseling to minimize the risk of having affected children for at risk couples.

Molecular genetic analysis of polycystic kidney disease 1 and polycystic kidney disease 2 mutations in pedigrees with autosomal dominant polycystic kidney disease.

BACKGROUND: Dysfunction of polycystin-1 or polycystin-2, the proteins encoded by polycystic kidney disease 1 (PKD1) and PKD2, respectively, are the cause of autosomal dominant PKD (ADPKD). This genetically heterogeneous monogenic disorder is the most common inherited kidney disease. The disease manifests are progressive cyst growth, renal enlargement, and renal failure, due to abnormal proliferation of kidney tubular epithelium. MATERIALS AND METHODS: In this study, mutation analysis of PKD1 and PKD2 genes in nine Iranian families was performed using next-generation sequencing. All patients met the diagnostic criteria of ADPKD. RESULTS: Mutations were found in all 9 families in PKD1 gene, comprising 2 novel and 7 previously reported mutations. No mutation in PKD2 was identified. CONCLUSION: Finding more mutations and expanding the spectrum of PKD1 and PKD2 mutations can increase the diagnostic value of molecular testing in the screening of ADPKD patients.

Homozygous TREM2 c.549del; p.(Leu184Serfs*5) variant causing Nasu-Hakola disease in three siblings in a consanguineous Iraqi family: Case report and review of literature.

BACKGROUND: The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease-associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu-hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early-onset dementia. METHODS: We studied 3 siblings with suspected NHD. Whole-exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents. RESULTS: We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early-onset dementia and bone lesions. CONCLUSION: These findings, alongside previous research, elucidate the clinical spectrum of TREM2-related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2-dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2-affected individuals.

Biallelic NDUFA4 Deletion Causes Mitochondrial Complex IV Deficiency in a Patient with Leigh Syndrome.

Oxidative phosphorylation involves a complex multi-enzymatic mitochondrial machinery critical for proper functioning of the cell, and defects herein cause a wide range of diseases called "primary mitochondrial disorders" (PMDs). Mutations in about 400 nuclear and 37 mitochondrial genes have been documented to cause PMDs, which have an estimated birth prevalence of 1:5000. Here, we describe a 4-year-old female presenting from early childhood with psychomotor delay and white matter signal changes affecting several brain regions, including the brainstem, in addition to lactic and phytanic acidosis, compatible with Leigh syndrome, a genetically heterogeneous subgroup of PMDs. Whole genome sequencing of the family trio identified a homozygous 12.9 Kb deletion, entirely overlapping the NDUFA4 gene. Sanger sequencing of the breakpoints revealed that the genomic rearrangement was likely triggered by Alu elements flanking the gene. NDUFA4 encodes for a subunit of the respiratory chain Complex IV, whose activity was significantly reduced in the patient's fibroblasts. In one family, dysfunction of NDUFA4 was previously documented as causing mitochondrial Complex IV deficiency nuclear type 21 (MC4DN21, OMIM 619065), a relatively mild form of Leigh syndrome. Our finding confirms the loss of NDUFA4 function as an ultra-rare cause of Complex IV defect, clinically presenting as Leigh syndrome.

Identification of a Novel Splice Site Mutation in RUNX2 Gene in a Family with Rare Autosomal Dominant Cleidocranial Dysplasia.

Background: Pathogenic variants of RUNX2, a gene that encodes an osteoblast-specific transcription factor, have been shown as the cause of Cleidocranial dysplasia (CCD), which is a rare hereditary skeletal and dental disorder with dominant mode of inheritance and a broad range of clinical variability. Due to the relative lack of clinical complications resulting in CCD, the medical diagnosis of this disorder is challenging, which leaves it underdiagnosed. Methods: : In this study, nine healthy and affected members of an Iranian family were investigated. PCR and sequencing of all exons and exon-intron boundaries of runt-related transcription factor 2 (RUNX2; NM_001024630) gene was performed on proband. Co-segregation analysis was conducted in the other family members for the identified variant. Additionally, a cohort of 100 Iranian ethnicity-matched healthy controls was screened by Amplification Refractory Mutation System PCR method. Results: The novel splice site variant (c.860-2A>G), which was identified in the intron 6 of RUNX2 gene, co-segregated with the disease in the family, and it was absent in healthy controls. Pathogenicity of this variant was determined by several software, including , human splicing finder, which predicts the formation or disruption of splice donor sites, splice acceptor sites, exonic splicing silencer sites, and exonic splicing enhancer sites. In silico analysis predicted this novel variant to be disease causing. Conclusion: The identified variant is predicted to have an effect on splicing, which leads to exon skipping and producing a truncated protein via introducing a premature stop codon.

Kabuki Syndrome: Identification of Two Novel Variants in KMT2D and KDM6A.

Kabuki syndrome (KS) is a rare genetic disorder characterized by the following 5 crucial symptoms: dysmorphic facial features, growth retardation, skeletal abnormalities, intellectual disability, and dermatoglyphic malformations. Studies show that most of the KS cases are caused by mutations or large deletions in the KMT2D gene, while the other cases show mutations in KDM6A. We studied 2 patients with suspected KS in 2 unrelated families by whole-exome sequencing to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants and check the segregation in other members of the families. Finally, the potential effects of the variants on the structure and function of respective proteins were tested using in silico predictions. Both affected members of the families showed typical manifestations of KS including intellectual disability, developmental delay, and abnormal facial characteristics. A novel heterozygous frameshift variant in the KMT2D gene, c.4981del; p.(Glu1661Serfs*61), and a novel hemizygote missense variant in the KDM6A gene, c.3301G>A; p.(Glu1101Lys), were detected in patients 1 and 2, respectively. The frameshift variant identified in the first family was de novo, while in the second family, the mother was also heterozygous for the missense variant. The frameshift variant in KMT2D is predicted to lead to a truncated protein which is functionally impaired. The Glu1101 residue of KDM6A (UTX) affected in the second patient is located in a conserved region on the surface of the Jumonji domain and predicted to be causative. Our findings provide evidence on the possible pathogenicity of these 2 variants; however, additional functional studies are necessary to confirm their impacts.

Identification of a novel MICU1 nonsense variant causes myopathy with extrapyramidal signs in an Iranian consanguineous family.

BACKGROUND: Ca2+ as a universal second messenger regulates basic biological functions including cell cycle, cell proliferation, cell differentiation, and cell death. Lack of the protein mitochondrial calcium uptake1 (MICU1), which has been regarded as a gatekeeper of Ca ions, leads to the abnormal mitochondrial Ca2+ handling, excessive production of reactive oxygen species (ROS), and increased cell death. Mutations in MICU1 gene causes a very rare neuromuscular disease, myopathy with extrapyramidal signs (MPXPS), due to primary alterations in mitochondrial calcium signaling which demonstrates the key role of mitochondrial Ca2+ uptake. To date, 13 variants have been reported in MICU1 gene in 44 patients presented with the vast spectrum of symptoms. CASE PRESENTATION: Here, we report a 44-year-old Iranian patient presented with learning disability, muscle weakness, easy fatigability, reduced tendon reflexes, ataxia, gait disturbance, elevated hepatic transaminases, elevated serum creatine kinase (CK), and elevated lactate dehydrogenase (LDH). We identified a novel nonsense variant c.385C>T; p.(R129*) in MICU1 gene by whole exome sequencing (WES) and segregation analysis. CONCLUSIONS: Our finding along with previous studies provides more evidence on the clinical presentation of the disease caused by pathogenic mutations in MICU1. Finding more variants and expanding the spectrum of the disease increases the diagnostic rate of molecular testing in screening of this kind of diseases and in turn improves the quality of counseling for at risk couples and helps them to minimize the risks of having affected children.

Prevalence and Genotype Distribution of Human Papillomavirus Infection among 12 076 Iranian Women.

INTRODUCTION: Human papillomavirus (HPV) infection is one of the major health concerns of women in developing countries. This study gives an insight into the prevalence and genotype distribution of HPV infection and compares it with Pap smear results among Iranian women. METHODS: In this study, 12 076 Iranian women underwent routine examination from November 2016 to November 2018 using HPV Direct Flow CHIP System for HPV DNA typing. Cytology was undertaken for 5138 samples. RESULTS: Overall HPV prevalence was calculated at 38.68%. The most frequent HPV types were HPV 6, 16, 11, 62/81, 52 and 54. The most high-risk HPV (HR-HPV) types were HPV 16, 52, 18, 39, 31 and 51. These 2 groups represent approximately half of all HPV types detected, 47% and 55%, respectively. Among individuals who underwent cytological tests, 135 individuals (2.63%) were cytologically positive. In this group, 81 individuals (60%) were HPV positive, 62 (76%) of whom were HR-HPV positive, most frequently with HPV 16 (34%). CONCLUSION: This study highlights the urgent need for public education and early diagnosis using HPV screening tests to prevent cervical cancer.

Three Novel Variants identified in FBN1 and TGFBR2 in seven Iranian families with suspected Marfan syndrome.

BACKGROUND: Marfan syndrome (MFS) is a multi-systemic autosomal dominant disease of the connective tissue characterized by the early development of thoracic aneurysms/dissections, along with various manifestations of the ocular and skeletal systems. Due to the genetic and clinical heterogeneity, the clinical diagnosis of this disorder is challenging. Loss-of-function mutations in FBN1 (encodes fibrillin-1) lead to MFS type 1. Also, similar mutations in transforming growth factor ß receptor 2 (TGFBR2) gene cause MFS type 2. Both proteins involve in TGF-ß signaling. METHODS: In this study, genetic screening using a panel involving 14 genes, especially FBN1 and TGFBR2, were performed on seven representatives affected members of seven unrelated Iranian families suspected with MFS. To confirm the variants, Sanger sequencing was applied to other affected/unaffected members of the families. RESULTS: A total of 13 patients showed MFS manifestations. Using genetic screening, two novel and three previously reported variants in FBN1 were identified. We also detected two variants (a novel and a previously reported variant) in the TGFBR2 gene. CONCLUSION: In this study, we introduce three novel variants identified through gene screening in seven Iranian MFS families. This report is expected to considerably improve genetic counseling for Iranian MFS families. Early precise molecular diagnosis can be helpful for better management and improving the life expectancy of these patients.

A homozygote variant in the tRNA splicing endonuclease subunit 54 causes pontocerebellar hypoplasia in a consanguineous Iranian family.

BACKGROUND: Homozygous loss-of-function mutations in TSEN54 (tRNA splicing endonuclease subunit 54; OMIM: 608755) cause different types of pontocerebellar hypoplasias (PCH) including PCH2, PCH4, and PCH5. The study aimed to determine the possible genetic factors contributing to PCH phenotypes in two affected male infants in an Iranian family. METHODS: We subjected two affected individuals in a consanguineous Iranian family. To systematically investigate the susceptible gene(s), whole-exome sequencing was performed on the proband and a novel identified variant was confirmed by Sanger sequencing. We also analyzed 26 relatives in three generations using PCR-restriction fragment length polymorphism (PCR-RFLP) followed and confirmed by Sanger sequencing. RESULTS: Physical and medical examinations confirmed PCH in the patients. Besides, the proband showed bilateral moderate sensorineural hearing loss and structural heart defects as the novel phenotypes. The molecular findings also verified that two affected individuals were homozygote for the novel synonymous variant, NM_207346.2: c.1170G>A; p.(Val390Val), in TSEN54. PCR-RFLP and Sanger sequencing elucidated that the parents and 16 relatives were heterozygote for the novel variant. CONCLUSION: We identified a novel synonymous variant, c.1170G>A, in TSEN54 associated with PCH in an Iranian family. Based on this study, we strongly suggest using "TSENopathies" to show the overlapped phenotypes among different types of PCH resulted from TSEN causative mutations.

Novel homozygous variants in the TMC1 and CDH23 genes cause autosomal recessive nonsyndromic hearing loss.

BACKGROUND: Hereditary hearing loss (HL) is a heterogeneous and most common sensory neural disorder. At least, 76 genes have been reported in association with autosomal recessive nonsyndromic HL (ARNSHL). Herein, we subjected two patients with bilateral sensorineural HL in two distinct consanguineous Iranian families to figure out the underlying genetic factors. METHODS: Physical and sensorineural examinations were performed on the patients. Imaging also was applied to unveil any abnormalities in anatomical structures of the middle and inner ear. In order to decipher the possible genetic causes of the verified GJB2-negative samples, the probands were subjected to whole-exome sequencing and, subsequently, Sanger sequencing was applied for variant confirmation. RESULTS: Clinical examinations showed ARNSHL in the patients. After doing whole exome sequencing, two novel variants were identified that were co-segregating with HL that were absent in 100 ethnically matched controls. In the first family, a novel homozygous variant, NM_138691.2: c.530T>C; p.(lle177Thr), in TMC1 gene co-segregated with prelingual ARNSHL. In the second family, NM_022124.6: c.2334G>A; p.(Trp778*) was reported as a nonsense variant causing prelingual ARNSHL. CONCLUSION: These findings can, in turn, endorse how TMC1 and CDH23 screening is critical to detecting HL in Iranian patients. Identifying TMC1 and CDH23 pathogenic variants doubtlessly help in the detailed genotypic characterization of HL.

Influence of antioxidants' gene variants on risk of diabetes mellitus and its complications: a systematic review.

INTRODUCTION: Oxidative stress has a key role in pathophysiology of type 2 diabetes mellitus (T2DM) and its complications as a most common health problem. Due to controversial evidence regarding the association between antioxidants' gene varients and T2DM, our aim was a systematic review of the current meta-analyses. EVIDENCE ACQUISTION: All meta-analysis' studies which assessed the association of single nucleotide polymorphisms of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX), glutathione S transferase (GST), nitric oxide synthase (NOS) and nicotinamide adenine dinucleotide phosphate oxidase (NOX) with T2DM and its complications were systematically extracted from PubMed, Scopus and Web of Science databases up to January 2016. Results are reported according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). EVIDENCE SYNTHESIS: Among 131 articles recorded in initial search, 19 studies were in the topic just for eNOS (endothelial NOS), NOX, GST and SOD gene variants. G894T, 4b/a and T-786C variants (eNOS) were associated with DN (diabetic nephropathy). However no association between 4b/a variant and DR (diabetic retinopathy) was observed. Separate or combination of GSTM1 and GSTT1 null genotypes (GST gene) were associated with T2DM. GSTM1 and combination of GSTM1/GSTT1 null genotypes were associated with DN. Significant association between C242T variant (NOX) and T2DM or DN, and non-significant association with carotid atherosclerosis were seen. C allele of C47T variant (SOD) was protective against DN, DR and microvascular complications of diabetes. CONCLUSIONS: Finding gene polymorphisms involved in diabetes and its complications might be helpful in discovering new therapeutic approaches, as well as prevention which is currently as a main focus in personalized medicine.

Molecular Genetic Analysis of PKHD1 Mutations in Pedigrees With Autosomal Recessive Polycystic Kidney Disease.

INTRODUCTION: A wide variety of mutations are spread throughout the PKHD1 gene, which encodes a 4074-bp amino acid protein, namely fibrocystin/polyductin, and is responsible for all features of autosomal recessive polycystic kidney disease (ARPKD). Autosomal recessive polycystic kidney disease is a hereditary early-onset form of polycystic kidney disease characterized by fusiform dilation of collecting ducts and congenital hepatic fibrosis. The highest level of PKDH1 expression is in the kidneys of fetus and adults, suggesting the functionally importance of the gene in the mature kidney in addition to its role in kidney development. MATERIALS AND METHODS: Mutational analysis of the PKHD1 gene was performed in 11 families with a history of 1 to 6 fetuses or children affected by ARPKD, which either were aborted or died shortly after birth. Analyses were done using the Next Generation sequencing and Sanger sequencing techniques. RESULTS: Four novel mutations, including c.6469C>T, c.9218 G>A, c.10456T>C, and c.8863C>G, and 3 previously reported ones, including c.9524A>G, c.1095G>A, c.1123C>T, were identified. CONCLUSIONS: In view of high consanguineous marriages in Iranian population, the frequency of disease is expected to be higher than the world average.

The first case of NSHL by direct impression on EYA1 gene and identification of one novel mutation in MYO7A in the Iranian families.

OBJECTIVES: Targeted next-generation sequencing (NGS) provides a consequential opportunity to elucidate genetic factors in known diseases, particularly in profoundly heterogeneous disorders such as non-syndromic hearing loss (NSHL). Hearing impairments could be classified into syndromic and non-syndromic types. This study intended to assess the significance of mutations in these genes to the autosomal recessive/dominant non-syndromic genetic load among Iranian families. MATERIALS AND METHODS: Two families were involved in this research and two patients were examined by targeted next-generation sequencing. Here we report two novel mutations in the MYO7A and EYA1 genes in two patients detected by targeted NGS. They were confirmed by Sanger sequencing and quantitative real-time PCR techniques. RESULTS: In this investigation, we identified a novel mutation in MYO7A, c.3751G>C, p.A1251P, along with another previously identified mutation (c.1708C>T) in one of the cases. This mutation is located in the MYTH4 protein domain which is a pivotal domain for the myosin function. Another finding in this research was a novel de-novo deletion which deletes the entire EYA1 coding region (EX1-18 DEL). Mutations in EYA1 gene have been found in branchiootorenal (BOR) syndrome. Interestingly the patient with EYA1 deletion did not show any other additional clinical implications apart from HL. This finding might argue for the sole involvement of EYA1 function in the mechanism of hearing. CONCLUSION: This investigation exhibited that the novel mutations in MYO7A, c.3751G>C, p.A1251P, and EYA1, EX1-18 DEL, were associated with NSHL. Our research increased the mutation spectrum of hearing loss in the Iranian population.

SLC34A3 Intronic Deletion in an Iranian Kindred with Hereditary Hypophosphatemic Rickets with Hypercalciuria

Objective: To describe clinical findings, biochemical profile and genetic analysis in an Iranian kindred with hereditary hypophosphatemic rickets with hypercalciuria (HHRH). Methods: Clinical examination and biochemical profile results and gene analysis of 12 members of a family of a patient previously diagnosed with HHRH due to SLC34A3 mutation. Ten healthy controls were also evaluated. Results: Of the twelve family members three were homozygote and seven heterozygote for the same SLC34A3 variant found in the proband while two others were unaffected. All patients had significantly increased risk of kidney stone formation, bone deformities and short stature compared with unrelated healthy controls. The heterozygous patients displayed milder clinical symptoms compared with homozygous patients. In particular they had mild or no hypophosphatemia and they did not develop skeletal deformities. Recurrent renal stones and hypercalciuria were the main presentations of the heterozygous patients which may be confused with familial hypercalciuria. In addition, biochemical analysis showed significantly low serum sodium and elevated alkaline phosphatase levels in these patients. Conclusion: Genetic counseling and screening for SLC34A3 mutations can be helpful in adult onset phenotype with unexplained osteoporosis, bone deformities and especial recurrent renal stones. In subjects with vitamin D deficiency the results should be interpreted cautiously.

A Genotype-First Approach for Clinical and Genetic Evaluation of Wolcott-Rallison Syndrome in a Large Cohort of Iranian Children With Neonatal Diabetes.

OBJECTIVE: Wolcott-Rallison syndrome (WRS) is an extremely rare autosomal recessive condition, characterized by permanent neonatal diabetes mellitus (PNDM) associated with skeletal dysplasia, growth retardation and liver dysfunction. WRS is caused by biallelic mutations in the gene encoding eukaryotic translation initiation factor 2alpha kinase 3 (EIF2AK3). METHODS: As part of a comprehensive study on clinical and genetic investigation of neonatal diabetes in an Iranian population, 60 unrelated Iranian subjects referred with PNDM were analyzed. All the probands were screened for KCNJ11, INS, ABCC8 and EIF2AK3 using a polymerase chain reaction-based sequencing approach. RESULTS: We identified 9 different variants in EIF2AK3 in 11 unrelated Iranian probands, of which 5 variants were shown to be novel and not reported previously. The diagnosis of WRS was made by molecular genetic testing and confirmed by clinical re-evaluation of the subjects. Clinical follow up of the affected individuals shows that in at least some of them, PNDM was associated with short stature, failure to thrive, neurodevelopmental delay, epilepsy and hepatic and renal dysfunction. There was a strong family history of neonatal diabetes in the families of the probands with a high mortality rate. CONCLUSION: WRS is a common cause of PNDM in children of consanguineous parents. Furthermore, clinical diagnosis of WRS would have been delayed or possibly missed without genetic testing because this study shows that the associated features of WRS might be obscured by a diagnosis of PNDM. Therefore EIF2AK3 should be considered for any infant and young child with PNDM, particularly if the parents are related.