The Influence of Clustered DNA Damage Containing Iz/Oz and OXOdG on the Charge Transfer through the Double Helix: A Theoretical Study.

The genome-the source of life and platform of evolution-is continuously exposed to harmful factors, both extra- and intra-cellular. Their activity causes different types of DNA damage, with approximately 80 different types of lesions having been identified so far. In this paper, the influence of a clustered DNA damage site containing imidazolone (Iz) or oxazolone (Oz) and 7,8-dihydro-8-oxo-2'-deoxyguanosine (OXOdG) on the charge transfer through the double helix as well as their electronic properties were investigated. To this end, the structures of oligo-Iz, d[A1Iz2A3OXOG4A5]*d[T5C4T3C2T1], and oligo-Oz, d[A1Oz2A3OXOG4A5]*d[T5C4T3C2T1], were optimized at the M06-2X/6-D95**//M06-2X/sto-3G level of theory in the aqueous phase using the ONIOM methodology; all the discussed energies were obtained at the M06-2X/6-31++G** level of theory. The non-equilibrated and equilibrated solvent-solute interactions were taken into consideration. The following results were found: (A) In all the discussed cases, OXOdG showed a higher predisposition to radical cation formation, and B) the excess electron migration toward Iz and Oz was preferred. However, in the case of oligo-Oz, the electron transfer from Oz2 to complementary C4 was noted during vertical to adiabatic anion relaxation, while for oligo-Iz, it was settled exclusively on the Iz2 moiety. The above was reflected in the charge transfer rate constant, vertical/adiabatic ionization potential, and electron affinity energy values, as well as the charge and spin distribution. It can be postulated that imidazolone moiety formation within the CDL ds-oligo structure and its conversion to oxazolone can significantly influence the charge migration process, depending on the C2 carbon hybridization sp2 or sp3. The above can confuse the single DNA damage recognition and removal processes, cause an increase in mutagenesis, and harm the effectiveness of anticancer therapy.

Exploring the Role of the MUTYH Gene in Breast, Ovarian and Endometrial Cancer.

BACKGROUND: MUTYH germline monoallelic variants have been detected in a number of patients affected by breast/ovarian cancer or endometrial cancer, suggesting a potential susceptibility role, though their significance remains elusive since the disease mechanism is normally recessive. Hence, the aim of this research was to explore the hypothesis that a second hit could have arisen in the other allele in the tumor tissue. METHODS: we used Sanger sequencing and immunohistochemistry to search for a second MUTYH variant in the tumoral DNA and to assess protein expression, respectively. RESULTS: we detected one variant of unknown significance, one variant with conflicting interpretation of pathogenicity and three benign/likely benign variants; the MUTYH protein was not detected in the tumor tissue of half of the patients, and in others, its expression was reduced. CONCLUSIONS: our results fail to demonstrate that germinal monoallelic MUTYH variants increase cancer risk through a LOH (loss of heterozygosity) mechanism in the somatic tissue; however, the absence or partial loss of the MUTYH protein in many tumors suggests its dysregulation regardless of MUTYH genetic status.

Genetic Complexity in Recurrent Basal Cell Carcinoma: A MUTYH Variant Case Report.

The MYUTH gene plays a critical role in preserving the integrity of the human genome, with mutations being identified in several different cancer diagnoses. It serves its purpose by encoding a DNA glycosylase enzyme responsible for preventing oxidative damage through the excision of adenine that is incorrectly paired with guanine or cytosine. Mutations of the MUTYH gene have been most frequently associated with MUTYH-associated polyposis (MAP) and colorectal cancer. Biallelic mutations of the MUTYH gene are implicated in MAP, and carriers of this mutation have an increased lifetime risk of developing colorectal cancer of 43% to 100%, depending on the appropriate screening and surveillance steps taken. This case describes a patient with recurrent basal cell carcinomas (BCC) and subsequent genetic testing that revealed a pathogenic monoallelic mutation of the MUTYH gene, as well as the interventions that were subsequently performed. It highlights a potentially new patient population that would benefit from early screening to assess the risk of developing colorectal cancers as well as BCC.

A comprehensive characterization of the spectrum of MUTYH germline pathogenic variants in Latin America.

MUTYH-Associated Polyposis (MAP) is caused by biallelic pathogenic germline variants in the MUTYH gene. However, individuals harboring monoallelic MUTYH pathogenic variants in the presence of a positive family history have been reported to have a twofold increased risk of colorectal cancer (CRC) and extra colonic cancers. Our aim was to characterize the spectrum of monoallelic and biallelic germline MUTYH pathogenic variants in Latin American patients and to describe their clinical and genetic characteristics. Patients were identified from eight high-risk genetic cancer centers of five Latin American countries. Statistical analysis was performed using the two-sided P test using the Vassarstats statistical tools. Statistical significance was set at a p value ≤ 0.05. Of the 105 unrelated patients with cancer or colorectal polyposis, 84.8% and 15.2% carried pathogenic monoallelic and biallelic MUTYH variants, respectively. The most common pathogenic variants were p.Gly396Asp and p.Tyr179Cys (55% and 23%, respectively). The mean age at first diagnosis was 48.29 years (range 31-71) and 49.90 years (range 27-87) in biallelic and monoallelic MUTYH patients, respectively. CRC was the only cancer diagnosed in patients with biallelic MUTYH pathogenic variants (75%), while breast cancer (46.1%) was more common than CRC (24.7%) in individuals with monoallelic MUTYH pathogenic variants. We reported a high frequency of European founder variants in our diverse population. Some phenotypic differences from current studies were identified, such as a higher breast cancer burden in monoallelic carriers and a complete absence of extra-colon tumors in biallelic patients.

Sebaceomas in a Muir-Torre-like Phenotype in a Patient with MUTYH-Associated Polyposis.

This case report describes a case of a patient with MUTYH-associated polyposis (MAP), who presented with multiple sebaceomas in a Muir-Torre-like phenotype. MAP is caused by mutations in MUTYH, a base excision repair gene responsible for detecting and repairing the 8-oxo-G:A transversion caused by reactive oxygen species. MAP is associated with an increased risk of developing adenomatous polyps and colorectal cancer. Muir-Torre syndrome is a clinical phenotype of Lynch syndrome, which presents with multiple cutaneous sebaceous neoplasms. Lynch syndrome, like MAP, increases the likelihood of developing colorectal cancer but with a different pathogenesis and mode of inheritance. This case demonstrates that in a patient presenting with multiple sebaceous neoplasms, further workup and genetic testing may be indicated, not only for Muir-Torre and Lynch syndrome but also for MAP.

Epistasis between mutator alleles contributes to germline mutation spectrum variability in laboratory mice.

Maintaining germline genome integrity is essential and enormously complex. Although many proteins are involved in DNA replication, proofreading, and repair, mutator alleles have largely eluded detection in mammals. DNA replication and repair proteins often recognize sequence motifs or excise lesions at specific nucleotides. Thus, we might expect that the spectrum of de novo mutations - the frequencies of C>T, A>G, etc. - will differ between genomes that harbor either a mutator or wild-type allele. Previously, we used quantitative trait locus mapping to discover candidate mutator alleles in the DNA repair gene Mutyh that increased the C>A germline mutation rate in a family of inbred mice known as the BXDs (Sasani et al., 2022, Ashbrook et al., 2021). In this study we developed a new method to detect alleles associated with mutation spectrum variation and applied it to mutation data from the BXDs. We discovered an additional C>A mutator locus on chromosome 6 that overlaps Ogg1, a DNA glycosylase involved in the same base-excision repair network as Mutyh (David et al., 2007). Its effect depends on the presence of a mutator allele near Mutyh, and BXDs with mutator alleles at both loci have greater numbers of C>A mutations than those with mutator alleles at either locus alone. Our new methods for analyzing mutation spectra reveal evidence of epistasis between germline mutator alleles and may be applicable to mutation data from humans and other model organisms.

Prevalence and Distribution of MUTYH Pathogenic Variants, Is There a Relation with an Increased Risk of Breast Cancer?

BACKGROUND: MUTYH has been implicated in hereditary colonic polyposis and colorectal carcinoma. However, there are conflicting data refgarding its relationship to hereditary breast cancer. Therefore, we aimed to assess if MUTYH mutations contribute to breast cancer susceptibility. METHODS: We retrospectively reviewed 3598 patients evaluated from June 2018 to June 2023 at the Hereditary Cancer Unit of La Paz University Hospital, focusing on those with detected MUTYH variants. RESULTS: Variants of MUTYH were detected in 56 patients (1.6%, 95%CI: 1.2-2.0). Of the 766 patients with breast cancer, 14 patients were carriers of MUTYH mutations (1.8%, 95%CI: 0.5-3.0). The prevalence of MUTYH mutation was significantly higher in the subpopulation with colonic polyposis (11.3% vs. 1.1%, p < 0.00001, OR = 11.2, 95%CI: 6.2-22.3). However, there was no significant difference in the prevalence within the subpopulation with breast cancer (1.8% vs. 1.5%, p = 0.49, OR = 1.2, 95%CI: 0.7-2.3). CONCLUSION: In our population, we could not establish a relationship between MUTYH and breast cancer. These findings highlight the necessity for a careful interpretation when assessing the role of MUTYH mutations in breast cancer risk.

Breast cancers in monoallelic MUTYH germline mutation carriers have clinicopathological features overlapping with those in BRCA1 germline mutation carriers.

PURPOSE: Breast cancer patients referred to genetic counseling often undergo genetic testing with broad panels that include both breast cancer susceptibility genes as well as genes more specific for extramammary sites. As a result, patients are often incidentally found to have germline mutations in genes that are not necessarily related to breast cancer risk. One such gene is MUTYH. To understand the role MUTYH may play in breast cancer, the clinicopathological features of patients with monoallelic MUTYH germline mutation and breast cancer were examined. METHODS: The clinicopathological characteristics of the breast cancers from patients with monoallelic MUTYH mutation were compared to breast cancer patients with other germline mutations in known breast cancer susceptibility genes, including ATM, BRCA1/2, CHEK2, and PALB2. The breast cancer patients who received genetic counseling but tested negative for the aforementioned gene mutations were used as a control group. RESULTS: Histologic characteristics of the breast cancers arising in monoallelic MUTYH mutation carriers had significantly larger tumor size, higher tumor grade, and more high-risk biomarker profiles (i.e., Her2-positive and triple-negative) than breast cancer patients with susceptibility genes, except for BRCA1. MUTYH mutation carriers also showed a trend of more frequent intratumoral divergency in terms of tumor grade and biomarker profiles. CONCLUSION: Although germline monoallelic MUTYH mutation is not thought to confer a meaningfully increased risk of breast cancer development, it may contribute to pathological aggressiveness and diversity of breast cancers when they sporadically arise in MUTYH carriers.

Increased KRAS G12C Prevalence, High Tumor Mutational Burden, and Specific Mutational Signatures Are Associated With MUTYH Mutations: A Pan-Cancer Analysis.

The aim of this study was to determine the pan-cancer landscape of MUTYH alterations and the relationship between MUTYH mutations and potentially actionable biomarkers such as specific genomic alterations, tumor mutational burden, and mutational signatures. We used a large pan-cancer comprehensive genomic dataset from patients profiled (tissue next generation sequencing) during routine clinical care. Overall, 2.8% of 229 120 solid tumors had MUTYH alterations, of which 55% were predicted germline. Thirty tumor types had a 2% or greater MUTYH mutation rate. MUTYH-altered versus -WT cancers had significantly higher tumor mutational burden and more frequent alterations in KRAS G12C, but not in KRAS in general; these observations were statistically significant, especially in colorectal cancers. Across cancers, PD-L1 expression levels (immunohistochemistry) were not associated with MUTYH alteration status. In silico computation demonstrated that MUTYH mutational signatures are associated with higher levels of hydrophobicity (which may reflect higher immunogenicity of neoantigens) relative to several other signature types such as microsatellite instability. Survival of patients with MUTYH-altered versus -WT tumors was similar. In conclusion, comprehensive genomic profiling suggests that several features of MUTYH-altered cancers may be pharmacologically targetable. Drugs such as sotorasib (targeting KRAS G12C) and immune checkpoint inhibitors, targeting the increased mutational load and higher neo-antigen hydrophobicity/immunogenicity merit investigation in MUTYH-mutated malignancies.

Multiple colorectal adenomas syndrome: The role of MUTYH mutation and the polyps' number in clinical management and colorectal cancer risk.

BACKGROUND & AIMS: Multiple colorectal adenomas (MCRAs) can result from APC (AFAP) or biallelic MUTYH (MAP) mutations, but most patients are wild type and referred to as non-APC/MUTYH polyposis (NAMP). We aim to examine the risk of colorectal cancer (CRC) and the role of endoscopy in managing patients with MCRAs, with a specific focus on clinical features and genotype. METHODS: Records of MRCAs between 2000 and 2022 were retrospectively analysed. Patients were divided according to the genotype (MAP vs. NAMP) and the number of categorised polyps' burden (group 1: 10-24, group 2: 25-49, and group 3: 50-99 adenomas). Predictors of outcome were CRC-free survival (CRC-FS) and Surgery free-survival (S-FS). RESULTS: 220 patients were enrolled (NAMP n = 178(80.0%)). CRC at diagnosis was more frequent in group 3 (p = 0.01), without significant differences between the genotypes (p = 0.20). At a follow-up of 83(41-164) months, 15(7%) patients developed CRC during surveillance. CRC-FS was not correlated to genotype (p = 0.07) or polyps' number (p = 0.33), while S-FS was similar in MAP and NAMP (p = 0.22) and lower in groups 2 and 3 (p = 0.0001). CONCLUSIONS: MAP and NAMP have the same CRC risk and no difference in treatment. Endoscopic surveillance compared favorably with surgery in avoiding CRC risk, even in patients with more severe colorectal polyposis.

MUTYH-associated polyposis: Is it time to change upper gastrointestinal surveillance? A single-center case series and a literature overview.

BACKGROUND: The presence of Spigelman stage (SS) IV duodenal polyposis is considered the most significant risk factor for duodenal cancer in patients with MUTYH-associated polyposis (MAP). However, advanced SS disease is rarely reported in MAP patients, and no clear recommendations on small bowel (SB) surveillance have been proposed in this patient setting. AIM: To research more because that case reports of duodenal cancers in MAP suggest that they may develop in the absence of advanced benign SS disease and often involve the distal portion of the duodenum. METHODS: We describe a series of MAP patients followed up at the Regina Elena National Cancer Institute of Rome (Italy). A literature overview on previously reported SB cancers in MAP is also provided. RESULTS: We identified two (6%) SB adenocarcinomas with no previous history of duodenal polyposis. Our observations, supported by literature evidence, suggest that the formula for staging duodenal polyposis and predicting risk factors for distal duodenum and jejunal cancer may need to be adjusted to take this into account rather than focusing solely on the presence or absence of SS IV disease. CONCLUSION: Our study emphasizes the need for further studies to define appropriate upper gastrointestinal surveillance programs in MAP patients.

Monoallelic deleterious MUTYH mutations generate colorectal cancer: A case report.

Here we reported a particular case of MUTYH-associated polyposis (MAP) that had only one rare heterozygous variant, but some particular clinical manifestations contributed to occur in this male patient by only one defective MUTYH allele were worth of further investigation. We reported a case of MAP. It is about a 33-year-old man with chief complaints of hematochezia who had multiple polyps that were found in his colon via colonoscopy. He followed his doctor's advice and performed a genetic analysis examination. Germline test was positive for a major heterozygous variant: chr1:45800165 on the MUTYH gene. MUTYH gene sequence analysis confirmed the following heterozygous variant: c.55CT (p.R19X) in exon 2 (ClinVar NM_001128425). Unfortunately, his mother and daughter have the ILK variant according to genetic analysis. However, this variant at the site was not detected in his father. Various types of polyps were found on repeated colonoscopy, which tended to become latent cancerous in the future. This case indicated that awareness of the risk of carcinogenesis of polyps in carriers of monoallelic variants might accordingly increase, and our understanding of the type of genetically related disease will be enhanced by us.

Complete Response to Immunotherapy in a Patient with MUTYH-Associated Polyposis and Gastric Cancer: A Case Report.

MUTYH-associated polyposis syndrome is an uncommon, autosomal recessive colorectal polyposis syndrome caused by biallelic inactivation of MUTYH. Most patients present with multiple colorectal polyps. However, other primary tumor sites have been described as less frequent. In this report, we describe the case of a young patient with a germline biallelic pathogenic MUTYH mutation with three different primary tumors. We focused on a metastatic gastric adenocarcinoma that presented with complete bowel obstruction secondary to extensive peritoneal carcinomatosis and achieved complete response upon treatment with immunotherapy. The patient's tumor presented with a high tumor mutational burden and a 100% combined positive score, which certainly contributed to the complete response to immunotherapy. To date, no studies have described the association of MUTYH-related tumors with high PD-L1 expression, but we hypothesized that it may be linked to the increased antigenicity of these cancers.

First report of medulloblastoma in a patient with MUTYH-associated polyposis.

AIMS: The mutY DNA glycosylase encoded by the MUTYH gene prevents G:C → T:A transversions through the base excision repair DNA repair system. Germline biallelic pathogenic variants in MUTYH cause an adenomatous polyposis called MUTYH-associated polyposis (MAP), an autosomal recessive disease (OMIM: 608456), with an increased risk of colorectal cancer. Digestive lesions in this context show an excess of G:C → T:A transversions, individualising a specific mutational signature associated with MUTYH deficiency called signature SBS36. Predisposition to other tumours in patients with germline biallelic pathogenic variants in MUTYH is suspected but remains unclear. We report the first case of medulloblastoma in a patient with MAP, carrying the homozygous pathogenic variant c.1227_1228dup, p.(Glu410Glyfs*43) in MUTYH. METHODS: Whole exome sequencing was performed on the medulloblastoma to enlighten single nucleotide variants of interest, microsatellite status and mutational signature. The objective was to determine the involvement of MUTYH deficiency in the oncogenesis of this medulloblastoma. RESULTS: The medulloblastoma has the mutational signature SBS36 and driver pathogenic variants in CTNNB1, PTCH1 and KDM6A corresponding to G:C → T:A transversions, suggesting a role of MUTYH deficiency in oncogenesis. CONCLUSIONS: Therefore, medulloblastoma could be a rare manifestation associated with germline biallelic pathogenic variants in MUTYH.

DARVIC: Dihedral angle-reliant variant impact classifier for functional prediction of missense VUS.

BACKGROUND: Of the large number of genetic variants identified, the functional impact for most of them remains unknown. Mutations in DNA damage repair genes such as MUTYH, which is involved in repairing A:8-oxoG mismatches caused by reactive oxygen species, can cause a higher risk of cancer. Mutations happening in other key genes such as TP53 also pose huge health threats and risk of cancer. The interpretation of genetic variants' functional impact is a forefront issue that needs to be addressed. Many different in silico methods based on different principles have been developed and applied in interpreting genetic variants. However, a current challenge is that many existing methods tend to overpredict the pathogenicity of benign variants. A new approach is needed to tackle this issue to improve genetic variant interpretation through the use of in silico methods. METHODS: In this study, we developed another protein structural-based approach called Dihedral angle-reliant variant impact classifier (DARVIC) to predict the deleterious impact of the coding-changing missense variants. DARVIC uses Ramachandran's principle of protein stereochemistry as the theoretical foundation and uses molecular dynamics simulations coupled with a supervised machine learning algorithm XGBoost to determine the functional impact of missense variants on protein structural stability. RESULTS: We characterized the features of dihedral angles in dynamic protein structures. We also tested the performance of DARVIC in MUTYH and TP53 missense variants and achieved satisfactory results in reflecting the functional impacts of the variants on protein structure. The method achieved a balanced accuracy of 84% in a functionally validated MUTYH dataset containing both benign and pathogenic missense variants, higher than other existing in silico methods. Along with that, DARVIC was able to predict 119 (47%) deleterious variants from a dataset of 254 MUTYH VUS. Further application of DARVIC to a functionally validated TP53 dataset had a balanced accuracy of 94%, topping other methods, demonstrating DARVIC's robustness. CONCLUSION: DARVIC provides a valuable tool to predict the functional impacts of missense variants based on their effects on protein structural stability and motion. At its current state, DARVIC performed well in predicting the functional impact of the missense variants both in MUTYH and TP53. We expect its high potential to predict functional impact for the missense variants in other genes.

The Unique Spectrum of MUTYH Germline Mutations in Colombian Patients with Extracolonic Carcinomas.

Background: Protein MUTYH, encoded by the gene MUTYH, is an important mismatch repair enzyme in the base-excision repair pathway of DNA repair. When genetically altered, different neoplastic conditions can arise. One of the widely known syndromes associated with MUTYH mutations is MUTYH-associated polyposis, a form of familial colorectal cancer syndrome. MUTYH may also be a driver in other familial cancer syndromes, as well as breast cancer and spontaneous cancer cases. However, some controversies about the role of these alterations in oncogenesis remain, especially when affected in a heterozygous way. Most available data on MUTYH mutations are on Caucasian patients. Material and Methods: We analyzed a small cohort of non-Caucasian, Colombian cancer patients with MUTYH germline heterozygous mutations, clinical features suggestive of familial cancer, and extensive genetic studies with no other mutations and without MUTYH-associated polyposis. Conclusion: With this case series, we intended to provide important data for the understanding of MUTYH as a possible driver of familial cancer, even when only heterozygous mutations are found.

[Surgical strategies for hereditary colorectal cancer]. / Operative Strategien bei hereditären kolorektalen Karzinomen.

Hereditary colorectal cancer (hCRC) represents a major diagnostic and therapeutic challenge. In addition to the usual diagnostic methods, the family history, histological confirmation and mutation analysis play an important role in identifying the type of hereditary CRC. The diagnosis and classification of hCRC are carried out based on the anamnesis, clinical presentation and histology and the further treatment is determined depending on the underlying type of hCRC. For familial adenomatous polyposis (FAP) coloproctomucosectomy after the end of puberty is always recommended, whereas the treatment recommendations for other forms, such as attenuated FAP (aFAP), MUTYH-associated polyposis (MAP) and hereditary nonpolyposis colon cancer (HNPCC, Lynch syndrome), range from close surveillance and endoscopic control, through segmental resection up to colectomy. Irrespective of the type of hCRC, the treatment regimens necessitate an individualized approach and require close interdisciplinary cooperation. When colorectal resection is performed, minimally invasive procedures should principally be prioritized and some studies could demonstrate a potential benefit of robotic surgery compared to laparoscopy.

Evolutionary Origin of MUTYH Germline Pathogenic Variations in Modern Humans.

MUTYH plays an essential role in preventing oxidation-caused DNA damage. Pathogenic germline variations in MUTYH damage its function, causing intestinal polyposis and colorectal cancer. Determination of the evolutionary origin of the variation is essential to understanding the etiological relationship between MUTYH variation and cancer development. In this study, we analyzed the origins of pathogenic germline variants in human MUTYH. Using a phylogenic approach, we searched MUTYH pathogenic variants in modern humans in the MUTYH of 99 vertebrates across eight clades. We did not find pathogenic variants shared between modern humans and the non-human vertebrates following the evolutionary tree, ruling out the possibility of cross-species conservation as the origin of human pathogenic variants in MUTYH. We then searched the variants in the MUTYH of 5031 ancient humans and extinct Neanderthals and Denisovans. We identified 24 pathogenic variants in 42 ancient humans dated between 30,570 and 480 years before present (BP), and three pathogenic variants in Neanderthals dated between 65,000 and 38,310 years BP. Data from our study revealed that human MUTYH pathogenic variants mostly arose in recent human history and partially originated from Neanderthals.

High prevalence of MUTYH associated polyposis among minority populations in Israel, due to rare founder pathogenic variants.

BACKGROUND: Autosomal recessive conditions are common in consanguineous populations. Since consanguinity is common in the Israeli Arab population, we evaluated the rate of MUTYH polyposis (MAP) among polyposis patients in this population and studied Pathogenic Variants (PVs) spectrum. METHODS: We reviewed health records of all Arab and Druze polyposis patients referred for counseling during 2013-2020 who fulfilled the Israeli Genetic Society criteria for MUTYH/APC testing, in a tertiary center in Northern Israel and four additional gastro-genetic clinics in Israel. RESULTS: The Northern cohort included 37 patients from 30 unrelated families; 8(26.6%) carried bi-allelic MUTYH PVs. The major variant p.Glu452del was detected in 6/8 Druze and Muslim families who shared the same haplotype. Other PVs detected in both cohorts included p.Tyr56Ter, p.His57Arg, c.849+3A>C, p.Ala357fs, and p.Tyr151Cys. Among bi-allelic carriers, 88% reported consanguinity, and 100% had positive family history for polyposis or colorectal cancer (CRC). Generally, the age of CRC was 10 years younger than reported in the general MAP population. CONCLUSIONS: MAP accounted for 27% of polyposis cases in the Arab population of Northern Israel. PVs spectrum is unique, with high frequency of the founder variant p.Glu452del. Our results may inform the genetic testing strategy in the Israeli Arab population.