1.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
2.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
3.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
4.Prognostic Value of Residual Circulating Tumor DNA in Metastatic Pancreatic Ductal Adenocarcinoma
Hongkyung KIM ; Jinho LEE ; Mi Ri PARK ; Zisun CHOI ; Seung Jung HAN ; Dongha KIM ; Saeam SHIN ; Seung-Tae LEE ; Jong Rak CHOI ; Seung Woo PARK
Annals of Laboratory Medicine 2025;45(2):199-208
Background:
Circulating tumor DNA (ctDNA) is a potential biomarker in pancreatic ductal adenocarcinoma (PDAC). However, studies on residual ctDNA in patients post-chemotherapy are limited. We assessed the prognostic value of residual ctDNA in metastatic PDAC relative to that of carbohydrate antigen 19-9 (CA19-9).
Methods:
ctDNA analysis using a targeted next-generation sequencing panel was performed at baseline and during chemotherapy response evaluation in 53 patients. Progression-free survival (PFS) and overall survival (OS) were first evaluated based on ctDNA positivity at baseline. For further comparison, patients testing ctDNA-positive at baseline were subdivided based on residual ctDNA into ctDNA responders (no residual ctDNA post-chemotherapy) and ctDNA non-responders (residual ctDNA post-chemotherapy). Additional survival analysis was performed based on CA19-9 levels.
Results:
The baseline ctDNA detection rate was 56.6%. Although clinical outcomes tended to be poorer in patients with baseline ctDNA positivity than in those without, the differences were not significant. Residual ctDNA post-chemotherapy was associated with reduced PFS and OS. The prognosis of ctDNA responders was better than that of non-responders but did not significantly differ from that of ctDNA-negative individuals (no ctDNA both at baseline and during post-chemotherapy). Compared with ctDNA responses to che-motherapy, a ≥ 50% decrease in the CA19-9 level had less effect on both PFS and OSbased on hazard ratios and significance levels. ctDNA could be monitored in half of the patients whose baseline CA19-9 levels were within the reference range.
Conclusions
Residual ctDNA analysis post-chemotherapy is a promising approach for predicting the clinical outcomes of patients with metastatic PDAC.
6.Factors Influencing Fluorescence-activated Cell Sorting for Multiple Myeloma Fluorescence in situ Hybridization: Real-world Experience
Jaeguk CHOI ; Kyunghee YU ; Seung-Tae LEE ; Saeam SHIN ; Jong Rak CHOI
Annals of Laboratory Medicine 2025;45(3):322-328
Background:
FISH is the standard method for detecting cytogenetic abnormalities (CAs) in patients with multiple myeloma, and pre-enrichment of plasma cells is recommended to increase detection rates. However, optimal strategies to ensure sufficient plasma cell retrieval when standard enrichment techniques fail remain underexplored. We investigated factors influencing the success of fluorescence-activated cell sorting (FACS) and assessed the use of direct FISH in cases in which FACS failed.
Methods:
A retrospective analysis was conducted on 457 bone marrow samples submitted for FISH between November 2016 and May 2022. FACS was considered successful when plasma cells (CD38+ and CD138+ cells) constituted > 1% of the total number of cells. Direct FISH was performed for samples with FACS failure.
Results:
FACS was successful in 70.9% of cases and had a high positivity rate (94.8%).Shorter sample transfer times significantly improved FACS success, with a 77.1% success rate for transfer times < 2 hrs, compared with 67.8% for longer times (P = 0.0388). Plasma cell percentage was a strong determinant of FACS success, with a median of 31.2% in successful cases versus 8.5% in failures (P < 0.0001). Even when FACS failed, direct FISH detected CAs in 43.6% of cases.
Conclusions
Plasma cell percentage and sample transfer time are critical factors influencing FACS success. While FACS-FISH demonstrates superior sensitivity in detecting CAs, direct FISH serves as a valuable alternative when FACS fails. These findings highlight the importance of optimizing sample handling and FISH protocols for accurate cytogenetic analysis of multiple myeloma.
7.Clinical Application of Optical Genome Mapping for Molecular Diagnosis of Facioscapulohumeral Muscular Dystrophy
Yeeun SHIM ; Jieun SEO ; Seung-Tae LEE ; Jong Rak CHOI ; Young-Chul CHOI ; Saeam SHIN ; Hyung Jun PARK
Annals of Laboratory Medicine 2024;44(5):437-445
Background:
Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy that mainly affects skeletal muscle. FSHD1 accounts for 95% of all FSHD cases and can be diagnosed based on the pathogenic contraction of the D4Z4-repeat array on chromosome 4q35. Genetic diagnosis of FSHD1 is challenging because of the large size and repetitive nature of the D4Z4 region. We evaluated the clinical applicability of optical genome mapping (OGM) for the genetic diagnosis of FSHD1.
Methods:
We included 25 individuals with clinically confirmed or suspected/probable FSHD and their families. Ultra-high-molecular-weight DNA from peripheral blood was labeled, stained, and imaged using a single-molecule OGM platform (Bionano Genomics Saphyr system). D4Z4 repeat size and haplotype information were analyzed using the manufacturer’s dedicated pipeline. We also compared the workflow and test time between Southern blot analysis and OGM.
Results:
We obtained concordant OGM and Southern blot results with 10 samples from patients with clinically confirmed FSHD. The D4Z4 repeat size differed within 1 unit between the Southern blot analysis and OGM. Among nine patients with clinically suspected or probable FSHD, six patients were confirmed to have pathogenic contractions by OGM.In our cohort, one de novo mosaic FSHD1 patient was successfully diagnosed with OGM.Moreover, OGM has a more straightforward and less time-consuming workflow than Southern blot analysis.
Conclusions
OGM enables accurate and reliable detection of pathogenic contraction of the D4Z4-repeat array and is a valuable tool for the genetic diagnosis of FSHD1.
8.Clinical Application of Optical Genome Mapping for Molecular Diagnosis of Facioscapulohumeral Muscular Dystrophy
Yeeun SHIM ; Jieun SEO ; Seung-Tae LEE ; Jong Rak CHOI ; Young-Chul CHOI ; Saeam SHIN ; Hyung Jun PARK
Annals of Laboratory Medicine 2024;44(5):437-445
Background:
Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy that mainly affects skeletal muscle. FSHD1 accounts for 95% of all FSHD cases and can be diagnosed based on the pathogenic contraction of the D4Z4-repeat array on chromosome 4q35. Genetic diagnosis of FSHD1 is challenging because of the large size and repetitive nature of the D4Z4 region. We evaluated the clinical applicability of optical genome mapping (OGM) for the genetic diagnosis of FSHD1.
Methods:
We included 25 individuals with clinically confirmed or suspected/probable FSHD and their families. Ultra-high-molecular-weight DNA from peripheral blood was labeled, stained, and imaged using a single-molecule OGM platform (Bionano Genomics Saphyr system). D4Z4 repeat size and haplotype information were analyzed using the manufacturer’s dedicated pipeline. We also compared the workflow and test time between Southern blot analysis and OGM.
Results:
We obtained concordant OGM and Southern blot results with 10 samples from patients with clinically confirmed FSHD. The D4Z4 repeat size differed within 1 unit between the Southern blot analysis and OGM. Among nine patients with clinically suspected or probable FSHD, six patients were confirmed to have pathogenic contractions by OGM.In our cohort, one de novo mosaic FSHD1 patient was successfully diagnosed with OGM.Moreover, OGM has a more straightforward and less time-consuming workflow than Southern blot analysis.
Conclusions
OGM enables accurate and reliable detection of pathogenic contraction of the D4Z4-repeat array and is a valuable tool for the genetic diagnosis of FSHD1.
9.Clinical Application of Optical Genome Mapping for Molecular Diagnosis of Facioscapulohumeral Muscular Dystrophy
Yeeun SHIM ; Jieun SEO ; Seung-Tae LEE ; Jong Rak CHOI ; Young-Chul CHOI ; Saeam SHIN ; Hyung Jun PARK
Annals of Laboratory Medicine 2024;44(5):437-445
Background:
Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy that mainly affects skeletal muscle. FSHD1 accounts for 95% of all FSHD cases and can be diagnosed based on the pathogenic contraction of the D4Z4-repeat array on chromosome 4q35. Genetic diagnosis of FSHD1 is challenging because of the large size and repetitive nature of the D4Z4 region. We evaluated the clinical applicability of optical genome mapping (OGM) for the genetic diagnosis of FSHD1.
Methods:
We included 25 individuals with clinically confirmed or suspected/probable FSHD and their families. Ultra-high-molecular-weight DNA from peripheral blood was labeled, stained, and imaged using a single-molecule OGM platform (Bionano Genomics Saphyr system). D4Z4 repeat size and haplotype information were analyzed using the manufacturer’s dedicated pipeline. We also compared the workflow and test time between Southern blot analysis and OGM.
Results:
We obtained concordant OGM and Southern blot results with 10 samples from patients with clinically confirmed FSHD. The D4Z4 repeat size differed within 1 unit between the Southern blot analysis and OGM. Among nine patients with clinically suspected or probable FSHD, six patients were confirmed to have pathogenic contractions by OGM.In our cohort, one de novo mosaic FSHD1 patient was successfully diagnosed with OGM.Moreover, OGM has a more straightforward and less time-consuming workflow than Southern blot analysis.
Conclusions
OGM enables accurate and reliable detection of pathogenic contraction of the D4Z4-repeat array and is a valuable tool for the genetic diagnosis of FSHD1.
10.Clinical Application of Optical Genome Mapping for Molecular Diagnosis of Facioscapulohumeral Muscular Dystrophy
Yeeun SHIM ; Jieun SEO ; Seung-Tae LEE ; Jong Rak CHOI ; Young-Chul CHOI ; Saeam SHIN ; Hyung Jun PARK
Annals of Laboratory Medicine 2024;44(5):437-445
Background:
Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy that mainly affects skeletal muscle. FSHD1 accounts for 95% of all FSHD cases and can be diagnosed based on the pathogenic contraction of the D4Z4-repeat array on chromosome 4q35. Genetic diagnosis of FSHD1 is challenging because of the large size and repetitive nature of the D4Z4 region. We evaluated the clinical applicability of optical genome mapping (OGM) for the genetic diagnosis of FSHD1.
Methods:
We included 25 individuals with clinically confirmed or suspected/probable FSHD and their families. Ultra-high-molecular-weight DNA from peripheral blood was labeled, stained, and imaged using a single-molecule OGM platform (Bionano Genomics Saphyr system). D4Z4 repeat size and haplotype information were analyzed using the manufacturer’s dedicated pipeline. We also compared the workflow and test time between Southern blot analysis and OGM.
Results:
We obtained concordant OGM and Southern blot results with 10 samples from patients with clinically confirmed FSHD. The D4Z4 repeat size differed within 1 unit between the Southern blot analysis and OGM. Among nine patients with clinically suspected or probable FSHD, six patients were confirmed to have pathogenic contractions by OGM.In our cohort, one de novo mosaic FSHD1 patient was successfully diagnosed with OGM.Moreover, OGM has a more straightforward and less time-consuming workflow than Southern blot analysis.
Conclusions
OGM enables accurate and reliable detection of pathogenic contraction of the D4Z4-repeat array and is a valuable tool for the genetic diagnosis of FSHD1.

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