Germline testing and genetic counseling in biliary tract cancer: an operative proposal to improve the state of art.

INTRODUCTION: A genetic predisposition seems to be involved in biliary tract cancer, but the prevalence of germline mutations in BTC remains unclear, and the therapeutic role of the germline pathologic variants is still unknown. AREA COVERED: The aim of the present work is to systematically review the data available on the hereditary predisposition of biliary tract cancer by a specific research on PubMed, in order to highlight the most important critical points and to define the current possible role of germinal testing and genetic counseling in this setting of patients. EXPERT OPINION: Basing on data already available, we decided to start in our institution a specific genetic protocol focused on biliary tract cancer patients, which includes genetic counseling and, if indicated, germline test. The inclusion criteria are: 1) Patient with personal history of oncologic disease other than BTC, 2) Patient with familiar history of oncologic disease (considering relatives of first and second grade), 3) Patient with ≤ 50 years old, 4) Patient presenting a somatic mutation in genes involved in DNA damage repair pathways and mismatch repair. The aim of the presented protocol is to identify germline pathogenic variants with prophylactic and therapeutic impact, and to collect and integrate a significant amount of clinical, familial, somatic, and genetic data.

Distribution of the C9orf72 hexanucleotide repeat expansion in healthy subjects: a multicenter study promoted by the Italian IRCCS network of neuroscience and neurorehabilitation.

Introduction: High repeat expansion (HRE) alleles in C9orf72 have been linked to both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD); ranges for intermediate allelic expansions have not been defined yet, and clinical interpretation of molecular data lacks a defined genotype-phenotype association. In this study, we provide results from a large multicenter epidemiological study reporting the distribution of C9orf72 repeats in healthy elderly from the Italian population. Methods: A total of 967 samples were collected from neurologically evaluated healthy individuals over 70 years of age in the 13 institutes participating in the RIN (IRCCS Network of Neuroscience and Neurorehabilitation) based in Italy. All samples were genotyped using the AmplideXPCR/CE C9orf72 Kit (Asuragen, Inc.), using standardized protocols that have been validated through blind proficiency testing. Results: All samples carried hexanucleotide G4C2 expansion alleles in the normal range. All samples were characterized by alleles with less than 25 repeats. In particular, 93.7% of samples showed a number of repeats ≤10, 99.9% ≤20 repeats, and 100% ≤25 repeats. Conclusion: This study describes the distribution of hexanucleotide G4C2 expansion alleles in an Italian healthy population, providing a definition of alleles associated with the neurological healthy phenotype. Moreover, this study provides an effective model of federation between institutes, highlighting the importance of sharing genomic data and standardizing analysis techniques, promoting translational research. Data derived from the study may improve genetic counseling and future studies on ALS/FTD.

The changing landscape of neonatal diabetes mellitus in Italy between 2003-2022.

CONTEXT: In the last decade Sanger method of DNA sequencing has been replaced by next generation sequencing (NGS). NGS is valuable in conditions characterized by high genetic heterogeneity such as neonatal diabetes mellitus (NDM). OBJECTIVE: To compare results of genetic analysis of patients with NDM and congenital severe insulin resistance (c.SIR) identified in Italy in 2003-2012 (Sanger) versus 2013-2022 (NGS). METHODS: We reviewed clinical and genetic records of 104 cases with diabetes onset before 6 months of age (NDM+c.SIR) of the Italian dataset. RESULTS: Fiftyfive patients (50 NDM + 5 c.SIR) were identified during 2003-2012 and 49 (46 NDM + 3 c.SIR) in 2013-2022. Twenty-year incidence was 1:103,340 (NDM) and 1:1,240,082 (c.SIR) live births. Frequent NDM/c.SIR genetic defects (KCNJ11, INS, ABCC8, 6q24, INSR) were detected in 41 and 34 probands during 2003-2012 and 2013-2022, respectively. We identified a pathogenic variant in rare genes in a single proband (GATA4) (1/42 or 2.4%) during 2003-2012 and in 8 infants (RFX6, PDX1, GATA6, HNF1B, FOXP3, IL2RA, LRBA, BSCL2) during 2013-2022 (8/42 or 19%, p= 0.034 vs 2003-2012). Notably, five among rare genes were recessive. Swift and accurate genetic diagnosis led to appropriate treatment: patients with autoimmune NDM (FOXP3, IL2RA, LRBA), were subjected to bone marrow transplant; patients with pancreas agenesis/hypoplasia (RFX6, PDX1) were supplemented with pancreatic enzymes and the individual with lipodystrophy caused by BSCL2 was started on metreleptin. CONCLUSIONS: NGS substantially improved diagnosis and precision therapy of monogenic forms of neonatal diabetes and congenital SIR in Italy.

Unveiling the SOD1-mediated ALS phenotype: insights from a comprehensive meta-analysis.

BACKGROUND AND OBJECTIVES: Amyotrophic lateral sclerosis associated with mutations in SOD1 (SOD1-ALS) might be susceptible to specific treatment. The aim of the study is to outline the clinical features of SOD1-ALS patients by comparing them to patients without ALS major gene variants and patients with variants in other major ALS genes. Defining SOD1-ALS phenotype may assist clinicians in identifying patients who should be prioritized for genetic testing. METHODS: We performed an extensive literature research including original studies which reported the clinical features of SOD1-ALS and at least one of the following patient groups: C9ORF72 hexanucleotide repeat expansion (C9-ALS), TARDBP (TARDBP-ALS), FUS (FUS-ALS) or patients without a positive test for a major-ALS gene (N-ALS). A random effects meta-analytic model was applied to clinical data extracted encompassing sex, site and age of onset. To reconstruct individual patient survival data, the published Kaplan-Meier curves were digitized. Data were measured as odds ratio (OR) or standardized mean difference (SMD) as appropriate. Median survival was compared between groups. RESULTS: Twenty studies met the inclusion criteria. We identified 721 SOD1-ALS, 470 C9-ALS, 183 TARDBP-ALS, 113 FUS-ALS and 2824 N-ALS. SOD1-ALS showed a higher rate of spinal onset compared with N-ALS and C9-ALS (OR = 4.85, 95% CI = 3.04-7.76; OR = 10.47, 95% CI = 4.32-27.87) and an earlier onset compared with N-ALS (SMD = - 0.45, 95% CI = - 0.72 to - 0.18). SOD1-ALS had a similar survival compared with N-ALS (p = 0.14), a longer survival compared with C9-ALS (p < 0.01) and FUS-ALS (p = 0.019) and a shorter survival compared with TARDBP-ALS (p < 0.01). DISCUSSION: This study indicates the presence of a specific SOD1-ALS phenotype. Insights in SOD1-ALS clinical features are important in genetic counseling, disease prognosis and support patients' stratification in clinical trials.

[The Management of Patients with Adult Autosomal Dominant Polycystic Kidney Disease (ADPKD) Requires a Multidisciplinary Approach].

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease. Its main feature is the progressive enlargement of both kidneys with progressive loss of kidney function. ADPKD is the fourth leading cause of terminal renal failure in the world. Even today there are still uncertainties and poor information. Patients too often have a renunciatory and passive attitude toward the disease. However, there are currently no internationally accepted clinical practice guidelines, and there are significant regional variations in approaches to the diagnosis, clinical evaluation, prevention, and treatment of ADPKD. Therefore, we believe it is important to point out the conduct of our specialist outpatient clinic for ADPKD, which from the beginning has developed a multidisciplinary approach (nephrologists, geneticists, psychologists, radiologists, nutritionists) to face the disease at 360° and therefore not only from a purely nephrological point of view. Such a strategy not only enables patients to receive a timely and accurate diagnosis of the disease, but also ensures that they will receive a thorough and focused follow-up over time, that can prevent or at least slow down the disease in its evolution providing patients with a serene awareness of their condition as much as possible.

Congenital solitary kidney in autosomal dominant polycystic kidney disease: Where do known genes end and the unknown begin?

We present the case of a 41-year-old man patient diagnosed with solitary left kidney with few cysts. He has a family history of unilateral renal agenesis (URA) but no for autosomal dominant polycystic kidney disease (ADPKD). Genetic testing revealed PKD1 gene intron 11 heterozygous nucleotide variant c.2854-23G>T, but no gene mutation implicated in URA. Just eight cases of ADPKD with one kidney have been recorded globally. PC1 and PC2 disruption, causing primary cilia malformation or absence resulting in relevant in the first embryonic development alteration. Cillia's crucial significance in many diseases will require more research.

Combined Presence in Heterozygosis of Two Variant Usher Syndrome Genes in Two Siblings Affected by Isolated Profound Age-Related Hearing Loss.

Sensorineural age-related hearing loss affects a large proportion of the elderly population, and has both environmental and genetic causes. Notwithstanding increasing interest in this debilitating condition, the genetic risk factors remain largely unknown. Here, we report the case of two sisters affected by isolated profound sensorineural hearing loss after the age of seventy. Genomic DNA sequencing revealed that the siblings shared two monoallelic variants in two genes linked to Usher Syndrome (USH genes), a recessive disorder of the ear and the retina: a rare pathogenic truncating variant in USH1G and a previously unreported missense variant in ADGRV1. Structure predictions suggest a negative effect on protein stability of the latter variant, allowing its classification as likely pathogenic according to American College of Medical Genetics criteria. Thus, the presence in heterozygosis of two recessive alleles, which each cause syndromic deafness, may underlie digenic inheritance of the age-related non-syndromic hearing loss of the siblings, a hypothesis that is strengthened by the knowledge that the two genes are integrated in the same functional network, which underlies stereocilium development and organization. These results enlarge the spectrum and complexity of the phenotypic consequences of USH gene mutations beyond the simple Mendelian inheritance of classical Usher syndrome.

Unravelling Novel SCN5A Mutations Linked to Brugada Syndrome: Functional, Structural, and Genetic Insights.

Brugada Syndrome (BrS) is a rare inherited cardiac arrhythmia causing potentially fatal ventricular tachycardia or fibrillation, mainly occurring during rest or sleep in young individuals without heart structural issues. It increases the risk of sudden cardiac death, and its characteristic feature is an abnormal ST segment elevation on the ECG. While BrS has diverse genetic origins, a subset of cases can be conducted to mutations in the SCN5A gene, which encodes for the Nav1.5 sodium channel. Our study focused on three novel SCN5A mutations (p.A344S, p.N347K, and p.D349N) found in unrelated BrS families. Using patch clamp experiments, we found that these mutations disrupted sodium currents: p.A344S reduced current density, while p.N347K and p.D349N completely abolished it, leading to altered voltage dependence and inactivation kinetics when co-expressed with normal channels. We also explored the effects of mexiletine treatment, which can modulate ion channel function. Interestingly, the p.N347K and p.D349N mutations responded well to the treatment, rescuing the current density, while p.A344S showed a limited response. Structural analysis revealed these mutations were positioned in key regions of the channel, impacting its stability and function. This research deepens our understanding of BrS by uncovering the complex relationship between genetic mutations, ion channel behavior, and potential therapeutic interventions.

Behavioral Phenotype, Electroclinical Features, and Treatment Options in Twins with Lrp2 Candidate Variants (Donnay-Barrow/Foar Syndrome).

The LRP2 gene encodes megalin (LRP-2/GP330), a large single-spanning transmembrane glycoprotein that serves as a multiligand endocytotic receptor and mediates the reabsorption of albumin in the proximal renal tubule. LRP2 is implicated in an autosomal recessive disorder characterized by dimorphisms, ocular anomalies, sensorineural deafness, proteinuria, epilepsy, and intellectual disability: a clinical condition called Donnai-Barrow syndrome (DBS) or facio-oculo-acoustico-renal (FOAR) syndrome. Pathogenic variants in LRP2 have been reported in fewer than 60 patients, but a detailed description of seizures, electroencephalographic patterns, imaging findings, behavioral phenotype, and long-term follow-up is still needed. We provide a clinical report of two mono-chorionic twins with LRP2-related disease manifesting developmental delay, autistic features, seizures, proteinuria, and sleep disorders. By sequencing clinical exome, LRP2 candidate rare variants, c.6815G > A, p. (Arg2272His), inherited from the mother and c.12725A > G, p. (Asp4242Gly), inherited from the father, were identified. During follow-up, at the age of 7, the main clinical features of the patients included insomnia, autistic features, severe psychomotor delay, and absent speech. The patients were under treatment with risperidone, antiseizure medications (ASMs), and supplementation of alpha-lactalbumin for self-injury and sleep disturbance. Our study confirmed the wide spectrum of behavioral and neurological and psychiatric features of this rare condition, suggesting new treatment options.

Expanding the spectrum of neonatal-onset AIFM1-associated disorders.

OBJECTIVES: Pathogenic variants in AIFM1 have been associated with a wide spectrum of disorders, spanning from CMT4X to mitochondrial encephalopathy. Here we present a novel phenotype and review the existing literature on AIFM1-related disorders. METHODS: We performed EEG recordings, brain MRI and MR Spectroscopy, metabolic screening, echocardiogram, clinical exome sequencing (CES) and family study. Effects of the variant were established on cultured fibroblasts from skin punch biopsy. RESULTS: The patient presented with drug-resistant, electro-clinical, multifocal seizures 6 h after birth. Brain MRI revealed prominent brain swelling of both hemispheres and widespread signal alteration in large part of the cortex and of the thalami, with sparing of the basal nuclei. CES analysis revealed the likely pathogenic variant c.5T>C; p.(Phe2Ser) in the AIFM1 gene. The affected amino acid residue is located in the mitochondrial targeting sequence. Functional studies on cultured fibroblast showed a clear reduction in AIFM1 protein amount and defective activities of respiratory chain complexes I, III and IV. No evidence of protein mislocalization or accumulation of precursor protein was observed. Riboflavin, Coenzyme Q10 and thiamine supplementation was therefore given. At 6 months of age, the patient exhibited microcephaly but did not experience any further deterioration. He is still fed orally and there is no evidence of muscle weakness or atrophy. INTERPRETATION: This is the first AIFM1 case associated with neonatal seizures and diffuse white matter involvement with relative sparing of basal ganglia, in the absence of clinical signs suggestive of myopathy or motor neuron disease.

Whole exome data prioritization unveils the hidden weight of Mendelian causes of male infertility. A report from the first Italian cohort.

Almost 40% of infertile men cases are classified as idiopathic when tested negative to the current diagnostic routine based on the screening of karyotype, Y chromosome microdeletions and CFTR mutations in men with azoospermia or oligozoospermia. Rare monogenic forms of infertility are not routinely evaluated. In this study we aim to investigate the unknown potential genetic causes in couples with pure male idiopathic infertility by applying variant prioritization to whole exome sequencing (WES) in a cohort of 99 idiopathic Italian patients. The ad-hoc manually curated gene library prioritizes genes already known to be associated with more common and rare syndromic and non-syndromic male infertility forms. Twelve monogenic cases (12.1%) were identified in the whole cohort of patients. Of these, three patients had variants related to mild androgen insensitivity syndrome, two in genes related to hypogonadotropic hypogonadism, and six in genes related to spermatogenic failure, while one patient is mutant in PKD1. These results suggest that NGS combined with our manually curated pipeline for variant prioritization and classification can uncover a considerable number of Mendelian causes of infertility even in a small cohort of patients.

Case report: Complex arterial findings in vascular ehlers-danlos syndrome with a novel COL3A1 variant and death at young age.

Vascular Ehlers-Danlos syndrome (vEDS) is a genetic disease caused by a pathogenic mutation in the COL3A1 gene. Despite its severe course, the rarity and extreme clinical variability of the disease can pose significant obstacles to a timely diagnosis. Early and accurate diagnosis may lead to improved patient outcomes by providing access to targeted pharmacological treatments like celiprolol and enhancing the management of vEDS-related complications. Herein, we report a patient harboring a novel de novo COL3A1 missense variant, in which the diagnosis was only possible belatedly due to delayed referral for genetic evaluation. The patient developed pulmonary complications, aneurysms, and vascular malformations, and died at the age of 26 years due to massive pulmonary bleeding.

APC-Related Phenotypes and Intellectual Disability in 5q Interstitial Deletions: A New Case and Review of the Literature.

The 5q deletion syndrome is a relatively rare condition caused by the monoallelic interstitial deletion of the long arm of chromosome 5. Patients described in literature usually present variable dysmorphic features, behavioral disturbance, and intellectual disability (ID); moreover, the involvement of the APC gene (5q22.2) in the deletion predisposes them to tumoral syndromes (Familial Adenomatous Polyposis and Gardner syndrome). Although the development of gastrointestinal tract malignancies has been extensively described, the genetic causes underlying neurologic manifestations have never been investigated. In this study, we described a new patient with a 19.85 Mb interstitial deletion identified by array-CGH and compared the deletions and the phenotypes reported in other patients already described in the literature and the Decipher database. Overlapping deletions allowed us to highlight a common region in 5q22.1q23.1, identifying KCNN2 (5q22.3) as the most likely candidate gene contributing to the neurologic phenotype.

Functional Characterisation of the Rare SCN5A p.E1225K Variant, Segregating in a Brugada Syndrome Familial Case, in Human Cardiomyocytes from Pluripotent Stem Cells.

Brugada syndrome (BrS) is an inherited autosomal dominant cardiac channelopathy. Pathogenic rare mutations in the SCN5A gene, encoding the alpha-subunit of the voltage-dependent cardiac Na+ channel protein (Nav1.5), are identified in 20% of BrS patients, affecting the correct function of the channel. To date, even though hundreds of SCN5A variants have been associated with BrS, the underlying pathogenic mechanisms are still unclear in most cases. Therefore, the functional characterization of the SCN5A BrS rare variants still represents a major hurdle and is fundamental to confirming their pathogenic effect. Human cardiomyocytes (CMs) differentiated from pluripotent stem cells (PSCs) have been extensively demonstrated to be reliable platforms for investigating cardiac diseases, being able to recapitulate specific traits of disease, including arrhythmic events and conduction abnormalities. Based on this, in this study, we performed a functional analysis of the BrS familial rare variant NM_198056.2:c.3673G>A (NP_932173.1:p.Glu1225Lys), which has been never functionally characterized before in a cardiac-relevant context, as the human cardiomyocyte. Using a specific lentiviral vector encoding a GFP-tagged SCN5A gene carrying the specific c.3673G>A variant and CMs differentiated from control PSCs (PSC-CMs), we demonstrated an impairment of the mutated Nav1.5, thus suggesting the pathogenicity of the rare BrS detected variant. More broadly, our work supports the application of PSC-CMs for the assessment of the pathogenicity of gene variants, the identification of which is increasing exponentially due to the advances in next-generation sequencing methods and their massive use in genetic testing.

A novel GRN mutation in an Italian patient with non-fluent variant of primary progressive aphasia at onset: a longitudinal case report.

Objectives: We report the clinical presentation and evolution of a case with a novel Progranulin gene (GRN) mutation and non-fluent language disturbances at onset. Materials and methods: A 60 year-old, white patient was followed due to a history of language disturbances. Eighteen months after onset, the patient underwent FDG positron emission tomography (PET), and at month 24 was hospitalized to perform neuropsychological evaluation, brain 3 T MRI, lumbar puncture for cerebrospinal fluid (CSF) analysis, and genotyping. At month 31, the patient repeated the neuropsychological evaluation and brain MRI. Results: At onset the patient complained prominent language production difficulties, such as effortful speech and anomia. At month 18, FDG-PET showed left fronto-temporal and striatal hypometabolism. At month 24, the neuropsychological evaluation reported prevalent speech and comprehension deficits. Brain MRI reported left fronto-opercular and striatal atrophy, and left frontal periventricular white matter hyperintensities (WMHs). Increased CSF total tau level was observed. Genotyping revealed a new GRN c.1018delC (p.H340TfsX21) mutation. The patient received a diagnosis of non-fluent variant of primary progressive aphasia (nfvPPA). At month 31, language deficits worsened, together with attention and executive functions. The patient presented also with behavioral disturbances, and a progressive atrophy in the left frontal-opercular and temporo-mesial region. Discussion and conclusion: The new GRN p.H340TfsX21 mutation resulted in a case of nfvPPA characterized by fronto-temporal and striatal alterations, typical frontal asymmetric WMHs, and a fast progression toward a widespread cognitive and behavioral impairment, which reflects a frontotemporal lobar degeneration. Our findings extend the current knowledge of the phenotypic heterogeneity among GRN mutation carriers.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19.

BACKGROUND: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. METHODS: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. RESULTS: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P = 1.1 × 10-4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3-8.2], P = 2.1 × 10-4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1-2635.4], P = 3.4 × 10-3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3-8.4], P = 7.7 × 10-8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10-5). CONCLUSIONS: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Clinical Features and Biomarkers to Differentiate Primary and Amyotrophic Lateral Sclerosis in Patients With an Upper Motor Neuron Syndrome.

OBJECTIVES: Differentiation between primary (PLS) and amyotrophic lateral sclerosis (ALS) entails relevant consequences for prognosis and management but is mostly unreliable at early stages. The objectives of the study are (1) to determine the features at onset that could help to differentiate between PLS and ALS, (2) to evaluate the diagnostic performance of an integrated serum biomarker panel, and (3) to identify the prognostic factors for patients presenting with upper motor neuron (UMN) syndrome. METHODS: We selected and retrospectively analyzed the clinical data of patients presenting with UMN syndrome. At the first evaluation, when available, serum biomarkers were measured using ultrasensitive single molecule array. RESULTS: The study population included 55 patients with PLS and 50 patients with ALS. Patients with PLS presented a longer time to first neurologic evaluation (PLS: 35.0 months, interquartile range [IQR] 17.0-38.0 months; ALS: 12.5 months, IQR 7.0-21.3 months; p < 0.01) and lower levels of neurofilament light chain (NfL) (PLS: 81.8 pg/mL, IQR 38.4-111.1 pg/mL; ALS: 155.9 pg/mL, IQR 85.1-366.4 pg/mL; p = 0.01). Two patients with PLS and 3 patients with ALS carried the C9orf72 expansion. NfL resulted an independent predictor of final diagnosis (odds ratio 1.01, 95% CI 1.00-1.02; p = 0.04) and an independent prognostic factor (hazard ratio 1.01, 95% CI 1.00-1.01; p < 0.01). DISCUSSION: NfL might help to differentiate patients with PLS from patients with ALS and to predict prognosis in patients with UMN 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.