Search Results (137)

Background: Riboflavin transporter deficiency type 2 is an ultra-rare, yet treatable, inborn error of metabolism. This autosomal recessive disorder is caused by pathogenic mutations in the SLC52A2 gene leading to progressive ataxia, polyneuropathy, and hearing and visual impairment. The early initiation of riboflavin therapy can prevent or mitigate the complications. To date, only 200 cases have been reported, mostly in consanguineous populations. The p.Gly306Arg founder mutation, identified in patients of Lebanese descent, is the most frequently reported worldwide. It was described in a homozygous state in a total of 21 patients. Therefore, studies characterizing the phenotypic spectrum of this mutation remain scarce. Methods: A retrospective review of charts of patients diagnosed with riboflavin transporter deficiency type 2 at a tertiary-care reference center in Lebanon was performed. Clinical, biochemical, and molecular profiles were analyzed and compared to reported cases in the literature. Results: A total of six patients from three unrelated families were diagnosed between 2018 and 2023. All patients exhibited the homozygous founder mutation, p.Gly306Arg, with variable phenotypes, even among family members. The median age of onset was 3 years. Diagnosis was achieved by exome sequencing at a median age of 5 years, as clinical and biochemical profiles were inconsistently suggestive. The response to riboflavin was variable. One patient treated with high-dose riboflavin recovered his motor function, while the others were stabilized. Conclusions: This study expands the current knowledge of the phenotypic spectrum associated with the p.Gly306Arg mutation in the SLC52A2 gene. Increased awareness among physicians of the common manifestations of this rare disorder is crucial for early diagnosis and treatment. In the absence of a consistent clinical or biochemical phenotype, the use of next-generation sequencing as a first-tier diagnostic test may be considered. Full article

Autosomal recessive types of both syndromic and non-syndromic inherited myopia are common in Saudi Arabia (SA) because many people marry their relatives. The prevalence of syndromic myopathies in SA, like Stickler syndrome (SS), Knobloch syndrome (KS), and Marfan syndrome (MFS), further complicates the disease spectrum. The causative genes linked to the Knobloch, Marfan, and Pierson syndromes are COL18A1, FBN1, and LAMB2, respectively. Additionally, we found recessive types of non-syndromic high myopia that have a high chance of causing retinal detachment, like those linked to LRPAP1 and LEPREL1. In these cases, regular evaluation and early intervention, including prophylactic laser photocoagulation and pars plana vitrectomy, may improve the outcome. Advancements in genetic testing for diagnosis and prevention accelerate detection, facilitate early interventions, and provide genetic counseling. The utilization of artificial intelligence (AI), machine learning (ML), and the advancement of gene therapy offer promising avenues for personalized care. We place a high value on using genetic knowledge to create a national screening program and patient registry aimed at understanding the national burden of myopia, knowing that we have a high rate of consanguinity, which reflects pathogenic homozygous alleles and founder mutations. This initiative will incorporate genetic counseling and leverage innovative technologies, which are crucial for disease management, early identification, and prevention in Saudi Arabia’s healthcare system. Full article

Background: Genetic insights from diverse populations are key to advancing cancer detection, treatment, and prevention. Unlike other Latin American countries, Colombia lacks a centralized registry for germline and somatic mutations in breast and ovarian cancer. This study describes the country’s first national variant registry, and the occurrence of recurrent mutations and potential founder effects in Colombia. Methods: To address this gap, we implemented the first capturing protocol using the REDCap system. In a group of 213 breast and/or ovarian cancer patients harboring genetic mutations, we collected genetic, clinical, and demographic data from 13 regional centers across Colombia. Statistical analyses assessed variant distribution and patient demographics. Results: Among 229 identified variants (105 germline, 124 somatic), most were classified as pathogenic or likely pathogenic (72.4% germline, 87% somatic). BRCA1 and BRCA2 accounted for the majority of recurrent mutations. Germline recurrent variants (seen >3 times) were recorded for BRCA1 (77.7%; 21/27) and BRCA2 (22.3%; 6/27). Similarly, recurrent somatic variants were identified for BRCA1 (82.6%; 38/46) and BRCA2 (17.4%; 8/46). Notably, four recurrent variants were previously reported as founder mutations: BRCA1 c.1674del (14.3% germline and 23.7% somatic), BRCA1 c.3331_3334del (33.3% germline and 52.6% somatic), BRCA1 c.5123C>A (52.4% germline and 23.7% somatic), and BRCA2 c.2808_2811del (50% germline and 50% somatic). Most cases originated from the Andean region, highlighting regional disparities. Conclusions: This registry offers the first overview of genetic variants in Colombian breast and ovarian cancer patients. Recurrent and region-specific mutations highlight the need for population-focused data to guide targeted screening and personalized care strategies. Full article

Background/Objectives: To correlate blood lead (Pb) levels with cancer risk in a prospective cohort of healthy women with non-occupational exposure to lead. We hypothesize that blood Pb levels can predict the risk of cancer in healthy women. Methods: The study was performed with women registered at the Hereditary Cancer Centre, Szczecin, aged 40 years and above between September 2010 and March 2024. A total of 2927 unaffected women were included in the study. Exclusion criteria were BRCA1 gene mutation, women with diagnosed cancer, and women with occupational exposures to Pb. All patients were asked about their occupational exposure and tested for the three Polish BRCA1 founder mutations (c.5266dupC/5382insC; c.181T > G/300T > G; c.4035delA/4153delA). Inductively coupled plasma mass spectrometry was used to measure blood Pb levels. The study was blinded to all scientists involved, and all samples were assayed in the absence of any knowledge about the clinical status of each participant. Results: There were 239 incident cancers diagnosed in the cohort after an average follow-up of 6 years. Compared to women with the lowest blood Pb concentration, women with higher blood Pb levels had a significantly increased risk of developing any cancer (HR = 1.46; (95% CI: 1.006–2.13; p = 0.046)). The association was stronger for women below the age of 50 years at study entry (HR = 2.59; (95% CI: 1.37–4.89; p = 0.003)). For women over 50 years of age, the results were statistically insignificant. Conclusions: This study suggests that blood Pb levels have the potential to be used as a marker of cancer risk in women under 50 years of age who have no known occupational exposure to this heavy metal. Further investigations using additional groups of women from Poland and other countries are needed for validate these findings. Full article

Osteogenesis imperfecta type VI is a rare autosomal recessive disorder characterized by bone fragility and defective mineralization, caused by pathogenic variants in the SERPINF1 gene. This study aimed to expand the understanding of OI type VI by analyzing clinical, radiological, and molecular findings in four patients from three unrelated families. Genotyping revealed two novel SERPINF1 variants, c.185G>T (p.Gly62Val) and c.992_993insCA (p.Glu331Asnfs), in a compound heterozygous state in one patient, and a known pathogenic variant, c.261_265dup (p.Leu89Argfs26), in a homozygous form in three patients. Clinical manifestations included early-onset fractures, severe skeletal deformities, impaired mobility, and growth failure. Radiological assessments revealed multilevel and multiplanar bone deformities and metaphyseal widening. RNA analysis demonstrated that the c.992_993insCA variant results in a truncated PEDF protein without triggering nonsense-mediated decay. Population screening identified a carrier frequency of 0.0044 for the c.261_265dup variant, suggesting a founder effect in the Tuvinian population. These findings expand the mutational spectrum of the SERPINF1 gene and provide new insights into the phenotypic variability of OI type VI. Our results highlight the importance of genetic screening in isolated populations and emphasize the need for further research to develop more effective therapeutic approaches for patients with limited response to bisphosphonate therapy. Full article

Background/Objectives: Cancer risk-reducing strategies in Ashkenazi women carrying founder variants have a cost-effective effect on reducing cancer morbidity and mortality. The British and US guidelines recommend BRCA1/2 (BRCA) screening among Ashkenazi Jewish people to identify high-risk individuals. BRCA status has not been investigated yet in the Jewish community of Rome. Methods: Patients were selected from the Family Cancer Clinic of the Umberto I University Hospital of Rome, and 38 unrelated families (28 of Roman Jewish and 10 of Libyan Jewish origin) were enrolled, comprising 44 subjects diagnosed with breast and/or ovarian cancer. Genetic counseling and germline BRCA testing were conducted. Haplotype analysis was performed. Results: Of the probands, 26.5% (9/34) from 7/28 unrelated families (25%) in the Jewish community of Rome harbored the known BRCA2 c.7007G>C, p. (Arg2336Pro) variant (rs28897743). Genetic analysis of the four unrelated carriers revealed a shared haplotype, indicating a potential founder effect. The length of the haplotype might confirm the Roman community to be the oldest among Jewish communities in Europe. Conclusions: This study indicates the BRCA2 c.7007G>C variant found in the Jewish community of Rome to be a founder variant. Finally, we underline a pressing need to address the increased risk of carrying BRCA mutations among individuals with Jewish heritage, and to enhance genetic counseling and screening efforts in ethnic minorities that are not otherwise routinely reached. Full article

Background/Objectives: Primary Ciliary Dyskinesia (PCD) is a rare genetic condition characterized by compromised mucociliary clearance and chronic respiratory manifestations. Anosmia, or the loss of smell, is a lesser-known but clinically relevant symptom that can significantly impact patient safety, nutritional status, and the overall quality of life. The RSPH4A (c.921+3_921+6delAAGT) founder mutation is highly prevalent among Puerto Rican individuals with PCD and may carry distinct phenotypic implications. This study aimed to evaluate olfactory function in Puerto Rican PCD patients with this mutation using the Brief Smell Identification Test (BSIT^®) and to assess associations with age and sex. Methods: We conducted a case–control study involving 30 participants, including 15 PCD patients with genetically confirmed RSPH4A mutations and 15 age- and sex-matched healthy controls. All participants completed the BSIT, and BSIT scores were compared by diagnosis, sex, and age. Results: PCD patients had significantly lower BSIT scores than controls (p = 0.0015). When stratified by sex, both male (p = 0.0289) and female (p = 0.0178) PCD patients demonstrated significantly lower BSIT scores compared to their respective healthy counterparts. Regression analysis showed a significant inverse correlation between age and BSIT score in the PCD group (r² = 0.2873; p = 0.0395), while no such relationship was observed in controls (r² = 0.0096; p = 0.7283). Among PCD patients, age-related decline in olfactory function was more pronounced in females (r² = 0.71; p = 0.005) than in males (r² = 0.31; p = 0.25). Conclusions: These findings demonstrate that the RSPH4A founder mutation is associated with measurable olfactory impairment in PCD patients, particularly in females and with advancing age. The routine assessment of olfactory function should be considered in the clinical evaluation of patients with PCD, as anosmia may represent a key phenotypic feature and contribute to disease burden. Full article

Background and aims: Although familial hypercholesterolemia (FH) is a common congenital cause of elevated low-density lipoprotein cholesterol (LDL-C), it remains underdiagnosed and undertreated worldwide due to its inherent genetic heterogeneity. This study aimed to determine the prevalence of genetic variants in a Lithuanian patient cohort with clinically diagnosed FH and evaluate their possible clinical implications. Methods: A total of 172 patients were included in the retrospective analysis. The study population comprised males and females ranging from 0 to 85 years of age, with LDL-C levels exceeding 4.9 mmol/L in adults and 3.9 mmol/L in children. The subjects were divided into four groups according to the Dutch Lipid Clinic Network (DLCN) criteria (definite, probable, possible, and unlikely). Children were analyzed separately. Next-generation sequencing (NGS) has been chosen as the most appropriate technique for genetic testing. All identified variants were categorized into three groups: (1) pathogenic, (2) likely pathogenic, and (3) variants of uncertain significance. Subjects without detected variants were classified into group (4) No mutation. Results: Women were diagnosed with FH significantly later than men (p = 0.033). Genetic testing identified FH-causing variants in 41.86% of subjects, with 20.93% carrying pathogenic variants, 9.88% likely pathogenic, and 11.05% variants of uncertain significance (VUS). Frequently identified pathogenic variants were c.654_656del p.(Gly219del) in LDLR and c.10580G>A p.(Arg3527Gln) in APOB, which are both linked to the founder effect. Genetic testing led to a reassessment of Dutch Lipid Clinic Network scores, increasing the number of individuals classified as “Definite FH” by 86.2%. Conclusions: The increasing use of NGS in FH has enhanced diagnostic capabilities and suggests population-specific genetic patterns. However, it also increases VUS detection, for which reclassification rates are still low and require strenuous efforts. Moreover, despite the benefits of genetic testing, significant gender disparities remain and require further attention. Full article

Background/Objectives: Oligopolyposis is a rare condition characterized by 10 to 100 adenomas in the colon. We aimed to investigate the clinical and endoscopic features of patients with oligopolyposis by comparing patients who carried pathogenic mutations and those who did not. Methods: This retrospective study included patients with a cumulative count of 10–100 adenomas found in the colon, at a single center. Clinical, endoscopic, and genetic data were analyzed. Results: A total of 155 patients were identified as having oligopolyposis. Genetic testing using a multigene panel was performed among 85 (55%) patients, while founder or family mutation testing was performed among 7 (4.5%) patients. No genetic testing was carried out in 63 (40.5%) patients. Pathogenic polyposis-related mutations were identified in 14 (16%) out of 85 patients who underwent genetic testing. Among these, seven (50%) mutations were found in the APC gene and seven (50%) in the MUTYH gene. A significantly higher proportion of mutation carriers were of Arab ethnicity (35.7% vs. 4.2%, p < 0.001). There was no significant difference between carriers and non-carriers with regard to family history of polyps or cancer. Colorectal cancer was found to be the initial presentation in three (21%) carriers and five (7%) non-carriers. Colonic surgeries were reported among 4 (28.6%) carriers and 13 (18.6%) non-carriers. No significant differences in the rates of colorectal cancer or death were observed between carriers and non-carriers. Conclusions: Only a small proportion of patients with oligopolyposis were found to be mutation carriers, with significant ethnic differences in mutation frequency but no notable differences in clinical features, colorectal cancer rates, or mortality. Full article

Schimke immuno-osseous dysplasia (SIOD) is a hereditary autosomal-recessive multi-system disorder with early mortality. It has variable clinical presentations, mainly characterised by disproportional short stature, steroid-resistant nephrotic syndrome, spondyloepiphyseal dysplasia, and T-cell immunodeficiency. In the majority of cases, SIOD is caused by pathogenic sequence variants (PSVs) in the SMARCAL1 gene that encodes protein involved in chromatin remodelling. SIOD is an ultra-rare condition, with an incidence of ~1 per 1–3 million live births; data on its genetic and clinical features are scarce. We conducted a retrospective study of 21 paediatric patients with SIOD diagnosed in our centre during the years 2003–2023. The most common extra-renal clinical features were short stature, osseous dysplasia, multiple stigmas, and leukopenia. Proteinuria of varying severity was observed in 16 cases. The five-year overall survival rate (OS) was 89% (95% CI 77–100%), and the ten-year OS was 10%. Next-generation sequencing (NGS) revealed the following PSVs in SMARCAL1 in 19 patients: c.355_500del, c.2542G>T, c.2290C>T, c.2562del, c.2533_2534del, c.1582A>C, c.1933C>T, c.1010T>C, c.1736C>T, c.2070dup, c.2551A>T, c.2149_2150dup, c.939delC, and c.1451T>A; the most common was c.2542G>T, resulting in premature translation termination (p.E848*), and it was found in 14 patients either in a homozygous (four patients) or compound-heterozygous (10 patients) state. According to microsatellite analysis, it is a “founder mutation” in Russia. Full article

Sleep disorders are characterized by impaired quality, timing, and amount of sleep, resulting in daytime distress and functioning. Primary ciliary dyskinesia (PCD) is a rare genetic condition characterized by oto-sino-pulmonary manifestations with multiple comorbidities, including sleep disorders. Background/Objectives: This pilot study aims to assess sleep disorders and neuropsychiatric comorbidities in Puerto Rican patients with the RSPH4A (c.921+3_921+6delAAGT) PCD founder mutation. However, the literature on sleep-related disorders and their neuropsychiatric comorbidities in PCD is limited. Methods: A cohort of fifteen patients with the RSPH4A (c.921+3_921+6delAAGT) founder mutation (six pediatric, nine adults) were evaluated for sleep quality, cognitive, neurodevelopmental history, and mood-related manifestations, followed by diagnostic polysomnography for sleep-disordered breathing and other sleep-related disorder detection. Results: Twelve out of fifteen (12/15, 80%) patients presented with sleep-related disorders, particularly obstructive sleep apnea where the median Pediatric AHI was 1.25/h (IQR: 1.1–1.75/h), T < 90: 0.1 min (IQR: 0–1.9 min) and adult AHI 1.3 (IQR: 0.9–8), T < 90: 0.2 min (IQR: 0–3.5 min). PCD patients also presented complex sleep behaviors, and more than half had sleep-related movement manifestations such as sleep-related Bruxism, PLMS, among others. All pediatric patients with OSA met criteria for an anxiety disorder, with a GAD-7 of 13 (IQR: 10.5–15.8); this association was not clearly seen in adults. Conclusions: Patients with PCD RSPH4A exhibited multiple sleep and neuropsychiatric manifestations, particularly OSA, sleep-related movement disorders and complex sleep behaviors. Further studies are needed to determine if these manifestations result from obstructive breathing, sleep mechanism disruption, or other neurodevelopmental impairment associated with this ciliopathy. Full article

Background/Objectives: Ductal carcinoma in situ (DCIS) is the most common non-invasive form of breast cancer. It is not clear to what extent DCIS is a part of the hereditary breast/ovarian cancer syndrome caused by BRCA1/2 mutations. Therefore, we investigated the association of BRCA1/2 mutations in patients with DCIS and assessed their impact on survival. Methods: We studied 564 Polish women with DCIS for six alleles in BRCA1 (c.181T>G, c.5266dupC, c.4035delA, c.3700_3704del5, c.68_69del and c.5251C>T) and four in BRCA2 (c.658_659del, c.3847_3848del, c.5946del and c.7913_7917del). To investigate the association of BRCA1/2 founder mutations with DCIS risk, we tested 4702 controls as a reference. To analyze survival, mutation carriers were followed for an average of 110 months. Results: A BRCA1 mutation was present in seven (1.24%) cases and in twenty-two (0.47%) controls (OR = 3.27, 95%CI 1.36 to 7.87, p = 0.01). A BRCA2 mutation was present in eight (1.42%) cases versus six (0.13%) controls (OR = 11.3, 95%CI 3.9 to 32.6, p < 0.0001). Three of the fifteen cases with BRCA1/2 mutations developed invasive ipsilateral or contralateral breast cancer, on average 6 years from the diagnosis of DCIS. There were no deaths reported among the 15 mutation carriers with DCIS. Conclusions: DCIS is a part of the hereditary breast/ovarian cancer syndrome caused by BRCA1/2 mutations. Women with DCIS should receive genetic counseling and testing for BRCA1/2 mutations. BRCA1/2 mutations may predispose women to a better DCIS prognosis, but further studies are needed. Full article

LAMA2-associated muscular dystrophy is a rare genetic disorder caused by pathogenic or likely pathogenic variants in the LAMA2 gene. The aim of this study is to characterize the spectrum of pathogenic/likely pathogenic variants in the LAMA2 gene among Russian patients, identify frequent pathogenic variants specific to this population, and estimate the prevalence of this disorder in Russia. Data were collected and analyzed from patients with confirmed diagnoses of LAMA2-associated muscular dystrophy using various molecular genetic methods in research centers from 2008 to 2024. Data were obtained from 90 unrelated patients with LAMA2-associated muscular dystrophy, out of which 83 presented with the more severe form, MDC1A1, while seven had milder form of LAMA2-associated muscular dystrophy. The most common pathogenic variants identified were nonsense mutations (40% of cases), followed by frameshift variants (29.3%), splicing variants (21.4%), gross deletions (5.3%), and missense variants (4%). It is worth noting that missense variants were found exclusively in patients with the milder form of LAMA2-associated muscular dystrophy. The most prevalent identified pathogenic variant was c.7536del (15%), characteristic of Slavic populations with an established founder effect. Additionally, a common pathogenic variant, c.8245-2A>G, was found predominantly in Kazan Tatars. The estimated prevalence of LAMA2-associated muscular dystrophy in Russia is approximately 1 in 117,700. Full article

Background/Objectives: Arterial Tortuosity Syndrome (ATS) is a rare, autosomal recessive connective tissue disorder characterized by arterial twists, abnormal bulges, constriction, and tears. Patients have distinctive features and disease manifestations. The syndrome’s full clinical spectrum and course remain incompletely understood. Methods: We sought to review the medical records of Qatari patients who had ATS. The cohort study included 21 patients who were genetically confirmed by mutations in the SLC2A10 gene. Results: The study revealed that the NM_030777.4(SLC2A10):c.243C>G (p.Ser81Arg) mutation in SLC2A10 leads to mild outcomes of no mortality and less morbidity. Novel features such as a flat philtrum, bulbous noses, bilateral nasolacrimal duct obstruction, allergic conjunctivitis, latent nystagmus, café au lait spots, eczema, dermatitis, allergic reactions, bilateral temporomandibular joint cysts, bilateral syndactyly (toes), parapelvic cysts, kidney malrotation, vesicoureteral reflux, and nephrolithiasis were identified in our cohort. Furthermore, rare features previously documented in a limited number of patients, including leg length discrepancy, epilepsy, and migraine headaches, were also observed in our cohort. Conclusions: Our data contributes new insights into the life course of ATS in Qatari patients. These findings underscore the importance of effective education strategies through repeated counseling aimed at preventing cousin marriage and the syndrome within the cohort. Full article

Background: Although genetic testing has improved our ability to diagnose Lynch syndrome (LS), there is still limited information on the extent of variations in the clinical and genetic landscape among LS variant heterozygotes (LSVH) in Africa. We sought to investigate the cancer spectrum, cumulative risk, and survival outcomes of LSVH with pathogenic/likely pathogenic variants (P/LPVs) in the MLH1 and MSH2 genes using a LS registry in South Africa over the last 30 years. Methods: A retrospective study was conducted to retrieve demographic, clinical, and genetic data of all LSVH with P/LPVs in the MLH1 and MSH2 genes from our LS registry. Genetic data were analyzed according to cancer spectrum, cumulative risk, and crude survival. We used the Chi-squared and t-test to assess differences between groups, and Kaplan–Meier survival analyses were used to analyze the cumulative risk and crude survival outcomes. A p-value < 0.05 at a 95% confidence interval was considered statistically significant. Results: We analyzed a total of 577 LSVH from 109 families. About 450 (78%) and 127 (22%) LSVH harbored a disease-causing mutation in MLH1 and MSH2, respectively. A South African founder PV (MLH1:c.1528C>T) accounted for 74% (n = 426) of all LSVH. CRC was the most common diagnosed cancer in both MLH1 and MSH2 LSVH. MLH1 LSVH had a younger age at cancer diagnosis than MSH2 LSVH (43 vs. 47 years, respectively, p = 0.015). Extracolonic cancers were predominantly higher in female LSVH (n = 33, 35%) than in male LSVH (n = 8, 7%) with the MLH1:c.1528C>T founder PV. The cumulative risk of any cancer and CRC at any age was higher in MLH1 LSVH than in MSH2 LSVH (p = 0.020 and p = 0.036, respectively). LSVH with the MLH1:c.1528C>T PV had a better 10-year overall survival after the first cancer diagnosis, particularly for CRC. Conclusions: LSVH with P/LPVs in the MLH1 and MSH2 genes exhibited significant gene- and sex-specific differences in cancer spectrum, cumulative risk and survival outcomes. Cancer risk and survival estimates described in this study can be used to guide surveillance and genetic counselling for LSVH in our population. Full article