Background: As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea. Methods: A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC. Results: The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%). Conclusions Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.

Purpose: Radio-Tartaglia syndrome (RTS; Mendelian Inheritance in Man [MIM]: 619312) is a rare neurodevelopmental disorder with few reported cases and limited research. It has recently been reported that the clinical features of RTS overlap with those of 1p36 deletion syndrome (1p36DS), a common chromosomal deletion characterized by clinical and molecular heterogeneity. This study aims to report on a Korean patient with RTS and compare the clinical and molecular features with those of patients with 1p36DS. Methods: A 3-year-old boy was brought to the hospital and underwent whole genome sequencing to evaluate developmental delay and multiple anomalies. This led to the identification of a de novo truncating variant in SPEN. We retrospectively investigated cases of 1p36DS that were either newly diagnosed at our institution or previously reported in the literature and databases. Results: The clinical profile of RTS includes developmental delay/intellectual disability, hypotonia, feeding difficulties, congenital heart defects, and facial dysmorphisms. SPEN is frequently found within the deleted region associated with 1p36DS. However, in all reported Korean cases of 1p36DS, the deletions were distal and did not involve SPEN; despite this, the clinical features of the disorder overlap considerably with those of RTS. Conclusion SPEN is a newly identified gene that plays a role in various developmental processes. Therefore, it is essential to include SPEN in genetic testing when diagnosing patients suspected of having a neurodevelopmental disorder. Additional research is required to explore the molecular and clinical features, as well as the prognosis, of patients with either an isolated SPEN mutation or one that co-occurs with 1p36DS.

Purpose: To investigate the clinical efficacy of rebamipide eyedrops in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome. Methods: The study included 50 patients with Sjögren’s syndrome accompanied by MGD treated with 0.05% (w/v) cyclosporine and 0.15% (w/v) sodium hyaluronate eyedrops. They were divided into two groups: 25 who added rebamipide eyedrops to their existing treatments and a control group of 25 whose treatments did not change. We evaluated the tear breakup time, the Schirmer test and conjunctival staining scores, meibomian gland quality and function, and eyelid margin irregularity before prescribing rebamipide eyedrops and 1 and 3 months after prescription. Additionally, before eyedrops use and 3 months later, meibographic scores were assessed via imaging of the meibomian gland and ocular surface disease index values also were assessed. Results: The rebamipide group exhibited significant improvements in the tear breakup time, conjunctival staining score, and ocular surface disease index compared to before treatment (all p < 0.05). However, the Schirmer test result, meibomian gland quality and function, and eyelid margin irregularity did not differ between either groups before or after treatment. After 3 months of eyedrop use, the rebamipide group exhibited a significantly higher tear breakup time (p < 0.01) and Schirmer test score (p < 0.01) than the control group (p = 0.01), and significantly lower ocular surface disease index and conjunctival staining scores (p < 0.01). Conclusions Addition of rebamipide eyedrops to the conventional treatment of patients with Sjögren’s syndrome accompanied by MGD effectively improves dry eye symptoms and the ocular surface parameters.

Background: TP53 mutations are associated with poor prognosis in myelodysplastic neoplasm (MDS) and AML. The updated 5th WHO classification and International Consensus Classification (ICC) categorize TP53-mutated MDS and AML as unique entities. We conducted a multicenter study in Korea to investigate the characteristics of TP53-mutated MDS and AML, focusing on diagnostic aspects based on updated classifications. Methods: This study included patients aged ≥ 18 yrs who were diagnosed as having MDS(N = 1,244) or AML (N = 2,115) at six institutions. The results of bone marrow examination, cytogenetic studies, and targeted next-generation sequencing, including TP53, were collected and analyzed. Results: TP53 mutations were detected in 9.3% and 9.2% of patients with MDS and AML, respectively. Missense mutation was the most common, with hotspot codons R248/ R273/G245/Y220/R175/C238 accounting for 25.4% of TP53 mutations. Ten percent of patients had multiple TP53 mutations, and 78.4% had a complex karyotype. The median variant allele frequency (VAF) of TP53 mutations was 41.5%, with a notable difference according to the presence of a complex karyotype. According to the 5th WHO classification and ICC, the multi-hit TP53 mutation criteria were met in 58.6% and 75% of MDS patients, respectively, and the primary determinants were a TP53 VAF > 50% for the 5th WHO classification and the presence of a complex karyotype for the ICC. Conclusions Collectively, we elucidated the molecular genetic characteristics of patients with TP53-mutated MDS and AML, highlighting key factors in applying TP53 mutation-related criteria in updated classifications, which will aid in establishing diagnostic strategies.

Background: Citrin deficiency is an autosomal recessive disorder caused by pathogenic variants in SLC25A13, presenting with various age-dependent clinical phenotypes and a broad spectrum of severity. However, few studies have examined the frequency and prevalence of citrin deficiency. We aimed to analyze the carrier frequency and disease prevalence in East Asian populations and Koreans. Methods: We comprehensively reviewed the literature and conducted a cross-sectional study to analyze genomic databases, including the Genome Aggregation Database (gnomAD), Korean Variant Archive (KOVA), and Tohoku Medical Megabank Organization (ToMMo), to identify pathogenic SLC25A13 variants in East Asian populations. A founder 3-kilobase (kb) insertion in intron 16 of SLC25A13 was investigated using whole-genome sequencing data from 681 Koreans with the Linux grep command. Results: Twenty-three pathogenic SLC25A13 variants were identified, with c.852_855del being the most common. Analysis of data from 17,501 East Asian individuals in the gnomAD and ToMMo databases revealed a carrier frequency of 1 in 62 people. Analysis of data from 7,214 individuals in the gnomAD and KOVA databases revealed a carrier frequency of 1 in 86, corresponding to an estimated disease prevalence of 1 in 29,502.c.1177+1G > A was identified as the most prevalent pathogenic variant in Koreans. The 3 kb insertion in intron 16 was detected in three out of 681 individuals, indicating a carrier frequency of 1 in 228. Conclusions The high carrier frequency of citrin deficiency in East Asians highlights the need for enhanced genetic screening and counseling, particularly in Korea, providing a valuable reference for future studies on genetic diversity and pathogenic variants in this population.

Purpose: To investigate the clinical efficacy of rebamipide eyedrops in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome. Methods: The study included 50 patients with Sjögren’s syndrome accompanied by MGD treated with 0.05% (w/v) cyclosporine and 0.15% (w/v) sodium hyaluronate eyedrops. They were divided into two groups: 25 who added rebamipide eyedrops to their existing treatments and a control group of 25 whose treatments did not change. We evaluated the tear breakup time, the Schirmer test and conjunctival staining scores, meibomian gland quality and function, and eyelid margin irregularity before prescribing rebamipide eyedrops and 1 and 3 months after prescription. Additionally, before eyedrops use and 3 months later, meibographic scores were assessed via imaging of the meibomian gland and ocular surface disease index values also were assessed. Results: The rebamipide group exhibited significant improvements in the tear breakup time, conjunctival staining score, and ocular surface disease index compared to before treatment (all p < 0.05). However, the Schirmer test result, meibomian gland quality and function, and eyelid margin irregularity did not differ between either groups before or after treatment. After 3 months of eyedrop use, the rebamipide group exhibited a significantly higher tear breakup time (p < 0.01) and Schirmer test score (p < 0.01) than the control group (p = 0.01), and significantly lower ocular surface disease index and conjunctival staining scores (p < 0.01). Conclusions Addition of rebamipide eyedrops to the conventional treatment of patients with Sjögren’s syndrome accompanied by MGD effectively improves dry eye symptoms and the ocular surface parameters.

Purpose: Radio-Tartaglia syndrome (RTS; Mendelian Inheritance in Man [MIM]: 619312) is a rare neurodevelopmental disorder with few reported cases and limited research. It has recently been reported that the clinical features of RTS overlap with those of 1p36 deletion syndrome (1p36DS), a common chromosomal deletion characterized by clinical and molecular heterogeneity. This study aims to report on a Korean patient with RTS and compare the clinical and molecular features with those of patients with 1p36DS. Methods: A 3-year-old boy was brought to the hospital and underwent whole genome sequencing to evaluate developmental delay and multiple anomalies. This led to the identification of a de novo truncating variant in SPEN. We retrospectively investigated cases of 1p36DS that were either newly diagnosed at our institution or previously reported in the literature and databases. Results: The clinical profile of RTS includes developmental delay/intellectual disability, hypotonia, feeding difficulties, congenital heart defects, and facial dysmorphisms. SPEN is frequently found within the deleted region associated with 1p36DS. However, in all reported Korean cases of 1p36DS, the deletions were distal and did not involve SPEN; despite this, the clinical features of the disorder overlap considerably with those of RTS. Conclusion SPEN is a newly identified gene that plays a role in various developmental processes. Therefore, it is essential to include SPEN in genetic testing when diagnosing patients suspected of having a neurodevelopmental disorder. Additional research is required to explore the molecular and clinical features, as well as the prognosis, of patients with either an isolated SPEN mutation or one that co-occurs with 1p36DS.

Purpose: Radio-Tartaglia syndrome (RTS; Mendelian Inheritance in Man [MIM]: 619312) is a rare neurodevelopmental disorder with few reported cases and limited research. It has recently been reported that the clinical features of RTS overlap with those of 1p36 deletion syndrome (1p36DS), a common chromosomal deletion characterized by clinical and molecular heterogeneity. This study aims to report on a Korean patient with RTS and compare the clinical and molecular features with those of patients with 1p36DS. Methods: A 3-year-old boy was brought to the hospital and underwent whole genome sequencing to evaluate developmental delay and multiple anomalies. This led to the identification of a de novo truncating variant in SPEN. We retrospectively investigated cases of 1p36DS that were either newly diagnosed at our institution or previously reported in the literature and databases. Results: The clinical profile of RTS includes developmental delay/intellectual disability, hypotonia, feeding difficulties, congenital heart defects, and facial dysmorphisms. SPEN is frequently found within the deleted region associated with 1p36DS. However, in all reported Korean cases of 1p36DS, the deletions were distal and did not involve SPEN; despite this, the clinical features of the disorder overlap considerably with those of RTS. Conclusion SPEN is a newly identified gene that plays a role in various developmental processes. Therefore, it is essential to include SPEN in genetic testing when diagnosing patients suspected of having a neurodevelopmental disorder. Additional research is required to explore the molecular and clinical features, as well as the prognosis, of patients with either an isolated SPEN mutation or one that co-occurs with 1p36DS.

Purpose: Radio-Tartaglia syndrome (RTS; Mendelian Inheritance in Man [MIM]: 619312) is a rare neurodevelopmental disorder with few reported cases and limited research. It has recently been reported that the clinical features of RTS overlap with those of 1p36 deletion syndrome (1p36DS), a common chromosomal deletion characterized by clinical and molecular heterogeneity. This study aims to report on a Korean patient with RTS and compare the clinical and molecular features with those of patients with 1p36DS. Methods: A 3-year-old boy was brought to the hospital and underwent whole genome sequencing to evaluate developmental delay and multiple anomalies. This led to the identification of a de novo truncating variant in SPEN. We retrospectively investigated cases of 1p36DS that were either newly diagnosed at our institution or previously reported in the literature and databases. Results: The clinical profile of RTS includes developmental delay/intellectual disability, hypotonia, feeding difficulties, congenital heart defects, and facial dysmorphisms. SPEN is frequently found within the deleted region associated with 1p36DS. However, in all reported Korean cases of 1p36DS, the deletions were distal and did not involve SPEN; despite this, the clinical features of the disorder overlap considerably with those of RTS. Conclusion SPEN is a newly identified gene that plays a role in various developmental processes. Therefore, it is essential to include SPEN in genetic testing when diagnosing patients suspected of having a neurodevelopmental disorder. Additional research is required to explore the molecular and clinical features, as well as the prognosis, of patients with either an isolated SPEN mutation or one that co-occurs with 1p36DS.

Purpose: Radio-Tartaglia syndrome (RTS; Mendelian Inheritance in Man [MIM]: 619312) is a rare neurodevelopmental disorder with few reported cases and limited research. It has recently been reported that the clinical features of RTS overlap with those of 1p36 deletion syndrome (1p36DS), a common chromosomal deletion characterized by clinical and molecular heterogeneity. This study aims to report on a Korean patient with RTS and compare the clinical and molecular features with those of patients with 1p36DS. Methods: A 3-year-old boy was brought to the hospital and underwent whole genome sequencing to evaluate developmental delay and multiple anomalies. This led to the identification of a de novo truncating variant in SPEN. We retrospectively investigated cases of 1p36DS that were either newly diagnosed at our institution or previously reported in the literature and databases. Results: The clinical profile of RTS includes developmental delay/intellectual disability, hypotonia, feeding difficulties, congenital heart defects, and facial dysmorphisms. SPEN is frequently found within the deleted region associated with 1p36DS. However, in all reported Korean cases of 1p36DS, the deletions were distal and did not involve SPEN; despite this, the clinical features of the disorder overlap considerably with those of RTS. Conclusion SPEN is a newly identified gene that plays a role in various developmental processes. Therefore, it is essential to include SPEN in genetic testing when diagnosing patients suspected of having a neurodevelopmental disorder. Additional research is required to explore the molecular and clinical features, as well as the prognosis, of patients with either an isolated SPEN mutation or one that co-occurs with 1p36DS.