Molecular Genetics & Genomic Medicine最新文献

Background: Heterozygous variants of sequestosome-1 gene (SQSTM1) have been reported in patients with various neurological disorders, whereas biallelic pathogenic variants of SQSTM1 can cause child-onset and multisystem neurodegeneration, including cerebellar ataxia, dystonia, and vertical gaze palsy (NADGP). Here, we describe two cases of NADGP in a Japanese family.

Methods: We performed clinical and genetic laboratory evaluations of the two patients and their healthy parents.

Results: By whole-exome sequencing, we identified compound heterozygous variants in SQSTM1(NM_003900.5): c.1A>G p.(Met1?) in the initial codon, and c.969G>A, located at the 3' end of exon 6, which is novel and seemingly a synonymous but is actually a truncating variant causing aberrant splicing. An SQSTM1 protein expression assay using urine-derived cells (UDCs) demonstrated that both variants (c.1A>G and c.969G>A) were unable to induce normal splicing of premessenger RNA. Cerebellar ataxia is a characteristic manifestation of this disorder; however, brain magnetic resonance imaging studies have not shown significant cerebellar atrophy. Our patients experienced chorea during adolescence.

Conclusions: Only a few reports have highlighted the presence of chorea; however, our findings suggest that NADGP should be considered as a differential diagnosis of hereditary chorea. This study also demonstrates the utility of UDCs, obtained using noninvasive approaches, in functionally analyzing genetic diseases.

Background: Impaired myocardial function and arrhythmia are important manifestations of Marfan syndrome (MFS). Studies assessing myocardial fibrosis in relation to these manifestations are scarce.

Methods: This cross-sectional, single-center study assessed ventricular volumes, ventricular function, and myocardial fibrosis by cardiac magnetic resonance imaging (CMR) in patients with MFS harboring a (likely) pathogenic FBN1 variant. The presence and extent of fibrosis were assessed by late gadolinium enhancement (LGE) and extracellular volume measurement (ECV). Data on 24-h Holter monitoring and clinical data were extracted from electronic patient records.

Results: The study included 32 unselected patients with MFS (median age 38 years [range 10-69], 41% women). No focal myocardial fibrosis was detected. Six patients (21%) had diffuse fibrosis (ECV > 29%). No association was found between the presence of diffuse fibrosis and clinically relevant myocardial dysfunction. Five patients (16%) had reduced left ventricular ejection fraction (LVEF < 55%). While all of these exhibited mitral annular disjunction (MAD), only two had ECV > 29%. Patients with MAD had increased indexed LV volumes (median end-diastolic volume, 92 mL/m² [IQR, 78-100] vs. 78 mL/m² [IQR, 71-87]; median end-systolic volume, 31 mL/m² [IQR, 23-46] vs. 22 mL/m² [IQR, 21-28]), also after adjusting for the presence of mitral and aortic valve regurgitation. No differences in ECV were seen between patients with and without MAD.

Conclusions: In this cohort of patients with MFS, focal myocardial fibrosis was not detected using CMR. Although diffuse fibrosis was observed in 21% of patients, no evident connection to clinically relevant myocardial dysfunction was found. Further studies should evaluate the impact of diffuse fibrosis on clinical outcome prediction.

Background: Sotos syndrome (SS) is a rare disorder characterized by overgrowth, distinctive facial features, and intellectual disability that is primarily caused by NSD1 pathogenic variants or 5q35 microdeletions.

Methods: We retrospectively analyzed the clinical characteristics and 339 anthropometric measurements over an average of 4.3 years of follow-up in 57 Korean children with SS. Sex-specific percentile curves for height, weight, and head circumference were developed using a generalized additive model that included factors such as location, scale, and shape.

Results: Males with SS demonstrated higher height before the age of 12.0, greater weight before 10.0, and larger head circumference before 15.5 compared to age- and sex-matched controls. Females with SS displayed higher height before 17.0, greater weight before 10.5, and larger head circumference before 12.0 compared to controls. Bone age was advanced compared to chronological age in 40% of males and 8% of females at their last visit. The predicted and target adult heights were not significantly different between groups. In subgroup analysis, the intragenic variant group (n = 48) showed a higher mean standard deviation score of height and weight in males, and head circumference in females compared to the microdeletion group (n = 9).

Conclusions: Korean children with genetically confirmed SS exhibited overgrowth in height, weight, and head circumference. Overgrowth phenotypes were more prominent in patients with NSD1 intragenic variants than in those with microdeletions. This is the first study to provide reference data on the growth of Korean children with SS.

Background: This study aimed to investigate the association between genetic variants of ERAP1 (OMIM: 606832) and psoriasis vulgaris (PsV) susceptibility in Inner Mongolia Han nationality.

Methods: For primary screening, the subjects included 142 PsV cases and 100 healthy controls without psoriasis. The 27 exons of ERAP1 gene were sequenced to screen significant genetic variants. For the validation study, the subjects included 1030 PsV cases and 965 healthy controls. A total of 18 mutations were detected for genetic variants of significance in primary screening and previously reported genetic variants.

Results: In primary screening stage, 13 genetic variants of ERAP1 showed an association with psoriasis. A total of 18 genetic variants were typed for the validation, and 12 genetic variants were associated with PsV in Inner Mongolia Han population. Stratified analysis showed significant differences in the allele frequencies of 8 ERAP1 genetic variants in cases with positive family history, and significant differences in allele frequencies among 9 ERAP1 genetic variants in patients with negative family history. A risk haplotype (TCCCTCCAGACC) was significantly associated with PsV, and the most risk haplotype was E730/K528/R127/E56.

Conclusion: ERAP1 gene mutation may be associated with PsV and HLA-C*06:02 in Han nationality in Inner Mongolia. A risk haplotype of four-nonsynonymous mutation (E730/K528/R127/E56) is associated with PsV.

Background: High sequence homology between CYP21A2 and CYP21A1P poses challenges to genetic diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD). Traditional genetic testing is unable to provide an accurate diagnosis due to the genetic complexity of CAH.

Methods: Deletions, duplications, and recombination breakpoints were precisely identified by long-read sequencing (LRS).

Results: This study presented a pregnant woman, a 21-OHD carrier detected by MLPA, and her husband, a normal subject also detected by MLPA. The fetus was suspected of having 21-OHD based on clinical presentations such as enlarged adrenal glands, atypical external genitalia and karyotyping of 46, XX. LRS further identified the fetus as having the most severe salt-wasting (SW) form of 21-OHD with a compound heterozygote genotype. One allele was TNXA/TNXB CH-2, while the other allele was CYP21A1P/CYP21A2 CH-8. LRS precisely determined the genotypes of the fetus's father and grandmother with duplications, which misdiagnosed by MLPA. The multidisciplinary team recommended immediate glucocorticoid and mineralocorticoid treatment for the child after birth to prevent life-threatening adrenal crisis.

Conclusions: LRS provides precise diagnosis for family members with CYP21A2 deletion or duplication, improving disease management and preventing potential adrenal crises. When used in pre-pregnancy genetic testing, LRS can indicate high genetic risk and guide the appropriate therapy during pregnancy and immediately after birth.

Background: Newborn screening (NBS) for isovaleric acidemia (IVA) is implemented via tandem mass spectrometry (MS/MS), but false-positive results are still common. In addition, NBS for IVA is limited by a lack of suitable biomarkers, especially after the use of pivaloylester-containing antibiotics.

Methods: We conducted a retrospective cohort study to explore the clinical correlation between antibiotic administration and false-positive results for isovalerylcarnitine (C5).

Results: A total of 509,313 newborns were recruited from the initial NBS study, only one of whom underwent genetic confirmation, conducted between 2015 and 2020. Significant associations between false-positive C5-carnitine screening results and treatment with pivalate-generating antibiotics were identified with retrospective analysis.

Conclusions: The current results highlight the detrimental effects of false-positive C5-carnitine screening results. Unless the licensing of pivalate-generating antibiotics for use during the neonatal period is reconsidered, a second-tier test for C5 determination will be necessary.

Background: Distal myopathies are genetic muscle disorders caused by mutations in various genes. A study found that mutations in adenylosuccinate synthetase-like 1 (ADSSL1) are associated with distal myopathy in nine patients from six unrelated families in South Korea. Previous research showed that affected individuals experienced distal muscle weakness starting in adolescence, along with mild facial muscle weakness, slightly elevated or normal serum creatine kinase (CK) levels, and the presence of a few rimmed vacuoles in muscle fibers or minimal chronic myopathic damage. Previously reported patients in this category exhibited an early age of symptom onset and severe muscle weakness. In this study, we present a case of two sisters who share the same mutation locus but display distinct disease phenotypes.

Methods: A literature review was conducted on distal myopathies in patients with ADSSL1 mutations, alongside a retrospective analysis of disease severity variability among siblings with a homozygous missense variant of ADSSL1.

Results: The study focuses on two sisters with differing disease manifestations despite carrying the same genetic mutation. The older sister showed lower ability in running and jumping compared to her peers at age 7 and experienced notable muscle weakness and atrophy by age 27, whereas the younger sister remained free of symptoms at age 30.

Conclusion: These findings suggest that mutations at the same locus can result in varying disease outcomes, emphasizing the complexity of predicting disease progression based solely on genetic mutations.

Aims: Familial frontotemporal dementia (fFTD) is an inherited neurodegenerative condition characterised by executive dysfunction, impairments in social cognition, behaviour and language. Although no disease-modifying interventions are currently available, several treatments are undergoing clinical trials. This study sought to understand the barriers and facilitators to taking part in such trials, as well as general perceptions of the treatments undergoing trial.

Method: Twelve interviews took place with fourteen participants: eight individuals who were genetically at-risk of developing fFTD, two individuals diagnosed with fFTD and four spousal carers. Their views and experiences of clinical trials were explored using thematic analysis.

Results: Five main themes were developed: (1) effects on the individual, (2) implications for others, (3) systemic considerations, (4) the impact of genetic status and disease progression and (5) the role of communication and understanding.

Conclusions: The decision to participate in clinical trials was said to be complex, involving consideration of logistical barriers alongside health implications. Participants identified potential advantages of participating in clinical trials to be direct health benefits and the ability to help others, however risks to participants and their families' physical and psychological wellbeing were also named. Relationships between organisations and participants were consistently considered to be important, with lack of psychological care at various timepoints post diagnosis; unclear communication and expectation-setting; and inadequate organisational collaboration all identified as barriers. Participants indicated that increased health-professional interest in FTD and an associated increase in opportunities would be key facilitators for greater participation in clinical trials.

Background: Myotonic Dystrophy type 1 (DM1) is an autosomal dominant disease with anticipation due to increased number of CTG repeats in the DMPK gene.

Methods: This retrospective, cohort study in Iceland assessed prevalence of DM1, molecular pathology, and patient ascertainment. Data was collected from all major hospitals in Iceland, Medical Director of Health, and independent clinics. Cohort criteria were diagnosis of DM1 on January 1, 2021, or time of death. Population-based Icelandic Genealogy Database of the Genetical Committee at the University of Iceland was used for genealogy.

Results: In Iceland, 221 individuals, including 19 obligate carriers, had been diagnosed with DM1 of which 144 were alive giving a point prevalence of 39 per 100,000 (four times the world average of 9.3). Genealogy analysis identified 45 first-degree families. Age-adjusted prevalence ranged between 11 and 66 per 100,000. Average potential years of life lost were 20.5 per person. Where information was available, 63% of ascertainment was based on family history in cascade testing.

Conclusion: The differences in age-adjusted prevalence suggest that the overall point prevalence is an underestimation due to underdiagnosis in younger age groups and lethality in oldest age group. Our data supports use of cascade testing to improve DM1 ascertainment.

Background: Bullous pemphigoid (BP) and atopic dermatitis (AD) are currently thought to be tightly related, yet studies of the mechanisms of co-morbidities are lacking.

Methods: We obtained GWAS data for BP (N = 376,274) and AD (N = 796,661) from the Finnish Genetic Research Program dataset and the UK Biobank, separately. Then, the following four analyses were performed: (1) cross-trait linkage disequilibrium score regression (LDSC) to assess the genetic correlation between BP and AD, (2) cross-phenotype association analysis (CPASSOC) to identify multiple effector loci shared by BP and AD, (3) transcriptome-wide association study (TWAS) to determine whether their cross-organizational expression patterns share genes with a common biological mechanism of relevance, and (4) bidirectional Mendelian randomization (MR) analysis to assess bidirectional causal effects of BP and AD.

Results: We found a positive genetic association between BP and AD (rg = 0.5476, p = 0.0495) as well as identified four pleiotropic loci and 59 common genes affecting BP and AD. Bidirectional MR analysis suggested that BP promotes the risk of AD.

Conclusions: We revealed a genetic link between BP and AD, which is associated with biological pleiotropy and causality. Awareness of the association between BP and AD helps dermatologists manage patients with these illnesses.