Consanguineous Iranian Family Research Articles

A Frameshift Variant in ANKRD24 Implicates Its Role in Human Non-Syndromic Hearing Loss.

Hearing loss (HL) is the most prevalent sensorineural disorders, affecting about one in 1000 newborns. Over half of the cases are attributed to genetic factors; however, due to the extensive clinical and genetic heterogeneity, many cases remain without a conclusive genetic diagnosis. The advent of next-generation sequencing methodologies in recent years has greatly helped unravel the genetic etiology of HL by identifying numerous genes and causative variants. Despite this, much remains to be uncovered about the genetic basis of sensorineural hearing loss (SNHL). Here, we report an Iranian consanguineous family with postlingual, moderate-to-severe autosomal recessive SNHL. After first excluding plausible variants in known deafness-causing genes using whole exome sequencing, we reanalyzed the data, using a gene/variant prioritization pipeline established for novel gene discovery for HL. This approach identified a novel homozygous frameshift variant c.1934_1937del; (p.Thr645Lysfs*52) in ANKRD24, which segregated with the HL phenotype in the family. Recently, ANKRD24 has been shown to be a pivotal constituent of the stereocilia rootlet in cochlea hair cells and interacts with TRIOBP, a protein already implicated in human deafness. Our data implicate for the first time, ANKRD24 in human nonsyndromic HL (NSHL) and expands the genetic spectrum of HL.

Identification of novel likely pathogenic variant in CDH23 causing non-syndromic hearing loss, and a novel variant in OTOGL in an extended Iranian family

BackgroundSensorineural hearing loss (SNHL) is a clinically and genetically heterogeneous group of disorders of the auditory system. SNHL can occur as a symptom in more than 400 syndromes, and mutations in more than 150 genes can lead to SNHL. Mutations in the GJB2 and GJB6 genes are among the most common causes of SNHL worldwide. Mutations in Cadherin 23 (CDH23) can cause Usher syndrome and/or non-syndromic hearing loss (NSHL).Material and methodsIn this study, the Whole Exome Sequencing (WES) was used to detect the cause of hearing loss in a large consanguineous Iranian family with two patients. All family members underwent a thorough Genotype–phenotype correlation assessment and co-segregation analysis to understand the inheritance pattern within the family. The candidate variants were further confirmed by Sanger sequencing. In addition, in silico analysis was performed to predict the functional impact of the variants; the interpretation of the variants was performed in accordance with the American College of Medical Genetics (ACMG) guidelines.ResultsWES results identified two novel variants, a homozygous missense variant in CDH23 (c.2961T > G) and a heterozygous splice site variant in OTOGL that was compatible with the autosomal recessive pattern of inheritance. Bioinformatics studies confirmed the pathogenic effects of novel variants. The c.2961T > G variant was classified as likely pathogenic.ConclusionsThe novel identified variant in the CDH23 was the cause of congenital profound progressive form of HL. Samples were not available from the second family to distinguish which variant is responsible for the molecular pathology of the disease. Further studies and functional examinations are suggested for investigating the role of OTOGL: c. 1863-1G > T in deafness.

Exome sequencing reveals neurodevelopmental genes in simplex consanguineous Iranian families with syndromic autism

Background and objectiveAutosomal recessive genetic disorders pose significant health challenges in regions where consanguineous marriages are prevalent. The utilization of exome sequencing as a frequently employed methodology has enabled a clear delineation of diagnostic efficacy and mode of inheritance within multiplex consanguineous families. However, these aspects remain less elucidated within simplex families.MethodsIn this study involving 12 unrelated simplex Iranian families presenting syndromic autism, we conducted singleton exome sequencing. The identified genetic variants were validated using Sanger sequencing, and for the missense variants in FOXG1 and DMD, 3D protein structure modeling was carried out to substantiate their pathogenicity. To examine the expression patterns of the candidate genes in the fetal brain, adult brain, and muscle, RT-qPCR was employed.ResultsIn four families, we detected an autosomal dominant gene (FOXG1), an autosomal recessive gene (CHKB), and two X-linked autism genes (IQSEC2 and DMD), indicating diverse inheritance patterns. In the remaining eight families, we were unable to identify any disease-associated genes. As a result, our variant detection rate stood at 33.3% (4/12), surpassing rates reported in similar studies of smaller cohorts. Among the four newly identified coding variants, three are de novo (heterozygous variant p.Trp546Ter in IQSEC2, heterozygous variant p.Ala188Glu in FOXG1, and hemizygous variant p.Leu211Met in DMD), while the homozygous variant p.Glu128Ter in CHKB was inherited from both healthy heterozygous parents. 3D protein structure modeling was carried out for the missense variants in FOXG1 and DMD, which predicted steric hindrance and spatial inhibition, respectively, supporting the pathogenicity of these human mutants. Additionally, the nonsense variant in CHKB is anticipated to influence its dimerization – crucial for choline kinase function – and the nonsense variant in IQSEC2 is predicted to eliminate three functional domains. Consequently, these distinct variants found in four unrelated individuals with autism are likely indicative of loss-of-function mutations.ConclusionsIn our two syndromic autism families, we discovered variants in two muscular dystrophy genes, DMD and CHKB. Given that DMD and CHKB are recognized for their participation in the non-cognitive manifestations of muscular dystrophy, it indicates that some genes transcend the boundary of apparently unrelated clinical categories, thereby establishing a novel connection between ASD and muscular dystrophy. Our findings also shed light on the complex inheritance patterns observed in Iranian consanguineous simplex families and emphasize the connection between autism spectrum disorder and muscular dystrophy. This underscores a likely genetic convergence between neurodevelopmental and neuromuscular disorders.

A Rare Combination of Compound Heterozygous Mutations in the PAH Gene in Three Unrelated Consanguineous Iranian Families with Classical Phenylketonuria.

The PAH gene mutations have been linked to the development of phenylketonuria (PKU), which is recognized as the most common inborn metabolic disorder, and is caused by a deficiency in the phenylalanine hydroxylase (PAH) enzyme. The Iranian population, known for its diversity and high consanguinity, offers a valuable sample for studying autosomal recessive disorders. Our study investigated three unrelated families with PKU from Iran, utilizing clinical, laboratory, and computational approaches. We performed direct PCR sequencing for 13 exons of the PAH gene on three Iranian patients who were diagnosed with PKU. Then, Sanger sequencing confirmed the segregation of the mutations from parents to probands. Pathogenicity predictor tools, including ACMG, CADD, SIFT, Polyphen-2, and Mutation Taster, were utilized to analyze the identified genetic variants. The three-dimensional structure of the mutant forms of the protein was predicted. We also analyzed the protein-protein interactions of PAH using the STRING database. All three patients exhibited rare compound heterozygosity rearrangements in the PAH gene (NM_000277.3). These included three missense variants: [c.533A>G/c.1222C>T], [c.526C>T/c.1222C>T], and [c.533A> / c.526C>T]. This study adds to the body of evidence establishing the association between PAH mutations and the development of PKU. We speculated that the conjunction of a high consanguinity rate in populations such as Iran, coupled with the founder effect, can give rise to atypical genetic profiles, as observed in the rearrangement of compound heterozygosity in this study Moreover, our research underscores the significance of genetic testing in the precise diagnosis of individuals affected by inborn errors of metabolism.

Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia

BackgroundAutosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals.MethodsThree members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022.ResultsAll cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis.ConclusionsHere, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.

Identification of a novel mutation of Platelet-Derived Growth Factor-C (PDGFC) gene in a girl with Non-Syndromic cleft lip and palate

BackgroundCleft lip with or without cleft palate (CL/CP) is a prevalent congenital malformation. Approximately 16 candidate loci for CL/CP have been identified in both animal models and humans through association or genetic linkage studies. One of these loci is the platelet-derived growth factor-C (PDGFC) gene. In animal models, a mutation in the PDGFC gene has been shown to lead to CL/CP, with PDGF-C protein serving as a growth factor for mesenchymal cells, playing a crucial role in embryogenesis during the induction of neural crest cells. In this study, we present the identification of a novel frameshift mutation in the PDGFC gene, which we hypothesize to be associated with CL/CP, within a consanguineous Iranian family. Case presentationThe proband was a 3-year-old girl with non-syndromic CL/CP. A history of craniofacial clefts was present in her family. Following genetic counseling, karyotype analysis and whole-exome sequencing (WES) were performed. Cytogenetic analysis revealed normal results, while WES analysis showed that the proband carried a homozygous c.546dupA (p.L183fs) mutation in the PDGFC gene. Sanger sequencing confirmed that her parents were carriers of the mutation. ConclusionThe c.546dupA (p.L183fs) mutation of PDGFC has not been previously reported and was not found in human genome databases. We speculate that the c.546dupA mutation of the PDGFC gene, identified in the Iranian patient, may be responsible for the phenotype of non-syndromic CL/CP (ns-CL/CP). Further studies are warranted to explore the specific pathogenesis of the PDGFC mutation in ns-CL/CP.

Identification of new variants in patients with mucopolysaccharidosis in consanguineous Iranian families.

Introduction: Mucopolysaccharidoses are a group of lysosomal storage disorders that include seven types that are classified based on the enzymes that are disrupted. Malfunction of these enzymes leads to the accumulation of glycosaminoglycans (GAGs) in various tissues. Due to genetic and clinical heterogeneity, diagnosing and distinguishing the different types is challenging. Genetic methods such as whole exome sequencing (WES) and Sanger sequencing are accurate methods for detecting pathogenic variants in patients. Methods: Thirty-two cases of mucopolysaccharidosis, predominantly from families with consanguineous marriages, were genetically examined. Out of these, fourteen cases underwent targeted sequencing, while the rest underwent WES. The results of WES were analyzed and the pathogenicity of the variants was examined using bioinformatics tools. In addition, a segregation analysis within families was carried out. Results: In most cases, a pathogenic or likely pathogenic variant was detected. Sixteen previously reported variants and six new variants were detected in the known IDS (c.458G>C, c.701del, c.920T>G), GNS (c.1430A>T), GALNS (c.1218_1221dup), and SGSH (c.149T>C) genes. Furthermore, we discovered a c.259G>C substitution in the NAGLU gene for the first time in three homozygous patients. This substitution was previously reported as heterozygous. Except for the variants related to the IDS gene, which were hemizygous, all the other variants were homozygous. Discussion: It appears that the high rate of consanguineous marriages in the families being studied has had a significant impact on the occurrence of this disease. Overall, these findings could expand the spectrum of pathogenic variants in mucopolysaccharidoses. Genetic methods, especially WES, are very accurate and can be used alone or in conjunction with other diagnostic methods for a more precise and rapid diagnosis of mucopolysaccharidoses. Additionally, they could be beneficial for family screening and disease prevention.

Second report of TEDC1-related microcephaly caused by a novel biallelic mutation in an Iranian consanguineous family.

Primary autosomal recessive microcephaly (MCPH) is a rare developmental disorder characterized by cognitive impairment, delayed neurodevelopment, and reduced brain size. It is a genetically heterogeneous condition, and several genes have been identified as associated with MCPH. In this study, we utilized whole-exome sequencing (WES) to identify disease-causing variations in two brothers from an Iranian family affected by MCPH, who had consanguineous parents. In the patients, we detected a novel homozygous missense mutation (c.806A > G, p.Gln269Arg) in the TEDC1 gene in one of the patients. Co-segregation analysis using Sanger sequencing confirmed that this variant was inherited from parents. The identified variant was evaluated for its pathogenicity and novelty using various databases. Additionally, bioinformatics tools were employed to predict the three-dimensional structure of the mutant TEDC1 protein. This study presents the second documented report of a mutation in the TEDC1 gene associated with MCPH. The identification of this novel biallelic mutation as a causative factor for MCPH in the proband further underscores the utility of genetic testing techniques, such as WES, as reliable diagnostic tools for individuals with this condition.

A novel ODAPH mutation causing amelogenesis imperfecta and its expression in human dental tissues

Background/purposeAmelogenesis imperfecta (AI), an assemblage of genetic diseases with dental enamel malformations, is generally grouped into hypoplastic, hypomaturation, and hypocalcified types. This study aimed to identify the genetic etiology for a consanguineous Iranian family with autosomal recessive hypocalcified AI. Materials and methodsDental defects were characterized, and whole exome analysis conducted to search for disease-causing mutations. Minigene assay and RT-PCR were performed to evaluate molecular consequences of the identified mutation and expression of the causative gene in human dental tissues. ResultsThe defective enamel of erupted teeth showed extensive post-eruptive failure and discoloration. Partial enamel hypoplasia and indistinct dentino-enamel junction were evident on unerupted teeth, resembling hypocalcified AI. A novel homozygous ODAPH (previously designated C4orf26) mutation of single-nucleotide deletion (NG_032974.1:g.5103del, NM_178497.5:c.67+1del) was identified to be disease-causing. The mutation would cause a frameshift to different ODAPH transcript variant (TV) products: p.(Ala23Hisfs∗29) for TV1 and p.(Gly23Aspfs∗140) for TV2. Both dental pulps of developing and exfoliating primary teeth expressed ODAPH TV2. ConclusionLoss-of-function ODAPH mutations can cause AI type IIIB (the hypocalcified, autosomal recessive type), rather than type IIA4 (the hypomaturation, pigmented autosomal recessive type). This study supports a hypothesis that the product of ODAPH TV2 is the single dominant ODAPH protein isoform critical for dental enamel formation and may also play an unappreciated role in development and homeostasis of dentin-pulp complex. Due to genetic heterogeneity and a nonideal genotype-phenotype correlation of AI, it is essential to perform genetic testing for patients with inherited enamel defects to make a definitive diagnosis.

A novel missense variant in EIF2B5 identified in a consanguineous Iranian family with vanishing white matter disease and a brief review of the literature

A novel missense variant in EIF2B5 identified in a consanguineous Iranian family with vanishing white matter disease and a brief review of the literature

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

BackgroundHuman 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 presentationWe 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.ConclusionsTo 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.

Exome Sequencing Identifies a Novel SGCA Gene Mutation in an Iranian Family with Limb Girdle Muscular Dystrophy: A Case Report

Introduction: Autosomal recessive limb-girdle muscular dystrophy (LGMD) is a rare congenital muscular dystrophy type. This inherited disease is one of the most common diseases resulting in severe physical health problems for infants. Genetic studies have shown that several gene mutations cause limb-girdle muscular dystrophy. This study aimed to report the case of a 10-year-old boy from an Iranian consanguineous family diagnosed with congenital muscular dystrophy and a causative genetic abnormality. Case Presentation: In this report, whole exome sequencing (WES) followed by Sanger sequencing was performed to diagnose the possible genetic defects in patients with LGMD. A novel homozygous disease-causing SGCA gene mutation (p.A107fs:c.319-329del) was found in exon 10 (NM_000023.4). Both parents were heterozygous for the detected mutation. Conclusions: It was concluded that the identified SGCA gene mutation was a pathogenic variant causing autosomal recessive LGMD.

Whole-exome sequencing reveals a likely pathogenic LMNA variant causing hypertrophic cardiomyopathy.

We studied the clinical and molecular features of a family with hypertrophic cardiomyopathy (HCM). A very heterogeneous disease affecting the heart muscle, HCM is mostly caused by variants in the proteins of sarcomeres. The detection of HCM pathogenic variants can affect the handling of patients and their families. Whole-exome sequencing (WES) was performed to assess the genetic cause(s) of HCM in a consanguineous Iranian family. Missense likely pathogenic variant c.1279C>T (p.Arg427Cys) within exon 7 of the LMNA gene (NM_170707) was found. The segregations were confirmed by polymerase chain reaction-based Sanger sequencing. Variant c.1279C>T (p.Arg427Cys) in the LMNA gene seemed to have been the cause of HCM in the family. A few LMNA gene variants related to HCM phenotypes have been recognized so far. Identifying HCM genetic basis confers significant opportunities to understand how the disease can develop and, by extension, how this progression can be arrested. Our study supports WES effectiveness for first-tier variant screening of HCM in a clinical setting.

Novel pathogenic CERKL variant in Iranian familial with inherited retinal dystrophies: genotype-phenotype correlation.

Inherited retinal dystrophies (IRDs) include a large chronic heterogeneity genetic disease. While many disease-causing pathogenic variants were involved in the progression of IRD, the Ceramide Kinase Like (CERKL) gene variant in Iranian patients is not well characterized. In this study, a consanguineous Iranian family with three generations was recruited whom presented with the clinical diagnosis of autosomal recessive IRD. By targeted next-generation sequencing (TGS) and Sanger sequencing, the proband was found to have a novel, pathological homozygous deletion variant c.560_568del (p.187_190del) of the CERKL gene (NM_001030311.2) that co-segregated with the disease in all affected family members. The Cerkl is highly expressed in the later four developmental retinal stages, playing a vital role in retina degeneration. Therefore, the identification of a novel, homozygous deletion CERKL variant c.560_568del (p.187_190del) in an IRD familial cohort descent provides insights into the molecular pathogenesis of IRD and facilitates genetic counseling and disease prediction.

Identification of a novel homozygous mutation of the BCKDHB gene in an Iranian patient with maple syrup disease using next-generation sequencing

BackgroundMaple syrup urine disease (MSUD) is an autosomal recessive disorder caused by decreased branched-chain alpha-keto acid dehydrogenase (BCKD) activity in human tissues. The BCKD enzyme is mostly active in the human body in the muscles and the brain; thus, genetic deficiency of the BCKD complex can result in neurological damage in patients. Deleterious mutations in BCKDHB, BCKDHA, DBT, and DLD genes have a significant impact on BCKD activity. MethodsIn this study, we described a case of MSUD in a consanguineous Iranian family without a history of metabolic disorders. A 7-year-old boy was diagnosed 21 days after birth with lethargy, feeding problems, and vomiting. Plasma amino acid concentration and level of ammonia were measured. And then, whole-exome sequencing (WES) 100× was used to identify causative mutation along with some bioinformatics analysis. ResultsA novel pathogenic homozygous mutation, c.552_553insA; P185Tfs*17, was detected in the BCKDHB gene's exon5. This variant was predicted as a pathogenic mutation using bioinformatics tools including Mutationtaster, Fathmm-mkl, Provean, DEOGEN2, SNPs&GO, PhyloP, and PhastCons. This mutation leads to a truncated protein in which conserved regions are lost. Besides, the variant is completely co-segregated with the disease in this family. ConclusionA novel pathogenic mutation c.552_553insA in the BCKDHB gene related to MSUD was diagnosed in an Iranian family. This finding from the present study can be efficient in upgrading mutation databases and recognizing MSUD causes.

Clinical Manifestations Associated with the Domain-Containing Protein 2 Gene Mutation in an Iranian Family with Spastic Paraplegia 54

Introduction: Spastic paraplegia type 54 (SPG54) is an autosomal recessive disorder caused by bi-allelic mutations in the DDHD-domain-containing protein 2 (DDHD2) gene. Worldwide, over 24 SPG54 families and 24 pathogenic variants have been reported. Our study aimed to describe the clinical and molecular findings of a pediatric patient from a consanguineous Iranian family with significant motor development delay, walking problems, paraplegia, and optic atrophy. Methods: The patient was a 7-year-old boy with severe neurodevelopmental and psychomotor problems. Neurological examinations, laboratory tests, electroencephalography, computed tomography scan, and brain magnetic resonance scan (MRI) were carried out for clinical evaluation. Whole-exome sequencing and in silico analysis were undertaken to identify the genetic cause of the disorder. Results: The neurological examination showed developmental delay, spasticity in the lower extremities, ataxia, foot contractures, and deep tendon reflexes in the extremities. The computed tomography scan was normal, but MRI revealed corpus callosum thinning with atrophic changes in the white matter. The genetic study reported a homozygous variant (c.856 C>T, p.Gln286Ter) in the DDHD2 gene. The homozygous state was confirmed by direct sequencing in the proband and his 5-year-old brother. This variant was not reported as a pathogenic variant in the literature or genetic databases and was predicted to affect the function of the DDHD2 protein. Conclusion: The clinical symptoms in our cases were similar to the previously reported phenotype of SPG54. Our results deepen the molecular and clinical spectrum of SPG54 to facilitate future diagnoses.

Identification of a homozygous frameshift mutation in the FGF3 gene in a consanguineous Iranian family: First report of labyrinthine aplasia, microtia, and microdontia syndrome in Iran and literature review.

To date, over 400 syndromes with hearing impairment have been identified which altogether constitute almost 30% of hereditary hearing loss (HL) cases around the globe. Manifested as complete or partial labyrinthine aplasia (severe malformations of the inner ear structure), type I microtia (smaller outer ear with shortened auricles), and microdontia (small and widely spaced teeth), labyrinthine aplasia, microtia, and microdontia (LAMM) syndrome (OMIM 610706) is an extremely rare autosomal recessive condition caused by bi-allelic mutations in the FGF3 gene. Using the whole-exome sequencing (WES) data of the proband, we analyzed a consanguineous Iranian family with three affected members presenting with congenital bilateral HL, type I microtia, and microdontia. We discovered the homozygous deletion c.45delC in the first exon of the FGF3 gene, overlapping a 38.72 Mb homozygosity region in chromosome 11. Further investigations using Sanger sequencing revealed that this variant co-segregated with the phenotype observed in the family. Here, we report the first identified case of LAMM syndrome in Iran, and by identifying a frameshift variant in the first exon of the FGF3 gene, our result will help better clarify the phenotype-genotype relation of LAMM syndrome.

A heterozygous missense variant in DLX3 leads to uterine leiomyomas and pregnancy losses in a consanguineous Iranian family

Uterine leiomyomas (ULs) are benign solid tumors arising from the uterine myometrium. They are the most common pelvic tumors among females of reproductive age. Despite the universal prevalence of ULs and its huge impact on women’s lives, the exact etiology and pathophysiologic mechanisms have not been fully understood. Numerous studies indicate that genetic factors play a crucial role in ULs development. This study aims to identify the probable genetic causes of ULs in a consanguineous Iranian family. Whole-exome sequencing (WES) on five family members with ULs revealed a likely pathogenic missense variant encoding for Y88C in the transactivation (TA) domain of DLX3 gene (c.263A > G; p.Y88C). Sanger sequencing of a total of 9 affected and non-affected family members indicated a segregation with disease with autosomal dominant inheritance. Moreover, targeted Sanger sequencing on 32 additional non-related patients with ULs showed none was heterozygous for this variant. MutPred2 predicted the pathogenicity of candidate variant by both phosphorylation and sulfation loss as actionable hypotheses. Project HOPE revealed that the identified variant residue is smaller and more hydrophobic comparing to the wild-type residue. I-TASSER and UCSF Chimera were also used for modeling and visualizing the predicted variant, respectively. This WES analysis is the first to report a variant in DLX3 variation associated with ULs pathogenicity in Iranian population highlighting the effectiveness of WES as a strong diagnostic method. However, further functional studies on this variant are needed to confirm the potential pathogenicity of this mutation.

ANXA1 mutation analysis in Italian patients with early onset PD

Recently, a novel pathogenic variant in Annexin A1 protein (c.4G > A, p.Ala2Thr) has been identified in an Iranian consanguineous family with autosomal recessive parkinsonism. The deficiencies of ANXA1 could lead to extracellular SNCA accumulation, defects in intracellular signaling pathways and synaptic plasticity causing parkinsonism. The aim of this study was to identify rare ANXA1 variants in 95 early-onset PD patients from South Italy. Sequencing analysis of ANXA1 gene revealed only 2 synonymous variants in PD patients (rs1050305, rs149033255). Therefore, we conclude that the recently published ANXA1 mutation is not a common cause of EOPD in Southern Italy.

Griscelli syndrome type 1: a novel pathogenic variant, and review of literature.

Griscelli syndrome type 1 (GS1) is a rare inherited autosomal recessive disease caused by a deleterious variant in the MYO5A gene and characterized by general hypopigmentation, neurological symptoms, motor disability, hypotonia, and vision abnormality. Only nine pathogenic variants in the MYO5A gene have been confirmed in association with the GS1. All of the reported pathogenic variants are truncating. Herein, two siblings from a consanguineous Iranian family with abnormal pigmentation and neurological symptoms were referred for genetic counseling. Whole-exome sequencing (WES) revealed a novel homozygous truncating variant c.1633_1634delAA (p.Asn545Glnfs*10) in the MYO5A gene, which was completely co-segregated with the phenotype in all affected and unaffected family members. Computational analysis and protein modeling demonstrated the deleterious effects of this variant on the structure and function of the protein. The variant, according to ACMG guidelines, was classified as pathogenic. Besides the novelty of the identified variant, our patients manifested more severe clinical symptoms and presented distal hyperlaxity in all four limbs, which was a new finding. In conclusion, we expanded the mutational and phenotypic spectrum of the GS1. Moreover, by studying clinical manifestations in all molecularly confirmed reported cases, provided a comprehensive overview of clinical presentation, and attempted to find a genotype-phenotype correlation.