KCNJ3 is a novel candidate gene for autosomal dominant pure hereditary spastic paraplegia identified using whole genome sequencing.

Hereditary spastic paraplegia (HSP) is a group of familial diseases characterized by progressive corticospinal tract degeneration. Clinically, patients present with lower-limb spasticity and weakness. To date, more than 80 genetic HSP types have been identified. Despite advances in molecular genetics, novel HSP gene discoveries are ongoing, with a low genetic diagnostic yield. In this study, we aimed to determine pathogenic variants in a family with HSP, which was not diagnosed through conventional genetic testing. We clinically characterized a large family and conducted whole genome sequencing (WGS) analysis of four affected and three unaffected individuals in the family to identify the genetic cause of HSP. This family had autosomal dominant pure (uncomplicated) late childhood-onset HSP. The patients' symptoms accelerated between the ages of 20 and 30. Brain magnetic resonance images typically showed white matter changes, a thin corpus callosum, and cerebellar atrophy. We identified a heterozygous missense variant, KCNJ3 c.1297T>G (p.Leu433Val), through WGS and family genetic analysis, confirmed by Sanger sequencing. We suggest that the identification of KCNJ3 c.1297T>G (p.Leu433Val) constitutes the discovery of a potential novel gene responsible for HSP in this family. This is the first study to report the possible role of a KCNJ3 variant in HSP pathogenesis. Our findings further expand the phenotypic and genotypic spectrum of HSP.

Novel In-Frame Deletion CNOT3 Variant in a Family With Intellectual Developmental Disorder With Speech Delay and Dysmorphic Facies.

Objectives: Intellectual developmental disorder with speech delay, autism, and dysmorphic facies (IDDSADF) is caused by heterozygous CNOT3 (MIM# 604910) variants on chromosome 19q13. This study aimed to identify and describe the clinical features of a Korean family with maternally inherited speech delay and intellectual and developmental disability to elucidate the underlying genetic mechanism. Methods: We conducted whole-exome sequencing and confirmatory Sanger sequencing on the proband, the mother, and unaffected grandparents with wild-type genotypes. Results: The phenotypes of the mother and 2 daughters presented muscular hypotonia, global developmental delay, speech delay, intellectual disability, macrocephaly, facial dysmorphic features, and focal corpus callosum hypoplasia. Whole-exome sequencing identified a novel in-frame deletion, c.2017_2019del (p.Phe673del) in CNOT3, located in the C-terminal negative on the TATA-less-box domain. Discussion: This report presents a new possible mechanism underlying IDDSADF caused by CNOT3 variants-an in-frame deletion. The findings enhance our understanding of early-life neurodevelopment and the genotype-phenotype relationships of IDDSADF caused by CNOT3 variants. In addition, this report could assist in early diagnosis and facilitate genetic counseling.

Effects of once-weekly dulaglutide on juvenile type 2 diabetes mellitus and obesity in Korea: a pilot study.

PURPOSE: We sought to investigate the effects and side effects of once-weekly dulaglutide treatment for type 2 diabetes mellitus (T2DM) in patients <18 years of age in Korea. METHODS: : From the Eulji University Hospital database, we identified all patients <18 years of age diagnosed with T2DM and treated with dulaglutide from January 1, 2017, to July 31, 2022. RESULTS: We identified 5 patients <18 years of age treated with dulaglutide for T2DM management. Their mean (standard deviation [SD]) age was 16.6 (0.5) years. Four (80%) patients were female. The mean (SD) body mass index was 29.4 (5.1) kg/m2, and the mean (SD) age at diagnosis was 15.2 (1.6) years. Four patients had been treated previously with metformin alone or in combination with insulin. Four patients were treated with 1.5 mg of dulaglutide and one was treated with 0.75 mg of dulaglutide. The mean (SD) hemoglobin A1c concentrations at baseline, 3 months after treatment, and 1 year after treatment, respectively, were 10.0% (2.2%), 6.5% (1.5%), and 6.7% (1.4%), with significant differences. In addition, at baseline, 3 months after treatment, and 1 year after treatment, the mean (SD) body weight values were 79.7 (13.3) kg, 80.2 (14.0) kg, and 81.1 (15.3) kg, with no significant difference. CONCLUSION: Use of once-weekly dulaglutide for juvenile T2DM ensures very good glycemic control, with few side effects and good adherence, indicating its potential as a promising therapeutic agent in this age group. Nationwide studies are warranted to confirm our results.

The first familial case of inherited intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) with a novel FBXO11 variant.

Intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) caused by germline de novo variants in FBXO11 was recently recognized as a novel intellectual disability (ID) syndrome through reverse phenotyping after whole-exome sequencing (WES). Fewer than 50 disease-causing de novo FBXO11 variants in IDDFBA are reported thus far. Here, we present the first report of a family showing autosomal dominantly inherited IDDFBA, harboring a novel heterozygous variant in FBXO11 (c.2401_2405dup;p. Gly803Leufs*6) identified by WES. In this family, the mother and two daughters showed mild ID and mild facial dysmorphism. This finding is expected to increase our understanding of the genotype-phenotype of IDDFBA and to facilitate genetic counseling for the disorder caused by FBXO11.

PDE3A variant associated with hypertension and brachydactyly syndrome in a patient with ischemic stroke caused by spontaneous intracranial artery dissection: A review of the clinical and molecular genetic features.

Hypertension and brachydactyly syndrome (HTNB; MIM 112410) is a rare, recently described, autosomal dominant syndromic disease characterized by the triad of brachydactyly type E (BDE), short stature, and hypertension. HTNB is caused by a heterozygous mutation in the PDE3A (MIM 123805) gene on chromosome 12p12; this gene encodes a member of the cGMP-inhibited cyclic nucleotide phosphodiesterase family. PED3A plays a role in many signal transduction pathways, including those involved in vascular smooth muscle proliferation and contraction, cardiac contractility, platelet aggregation, and hormone secretion. Here, we present a new case of HTNB in a 42-year-old patient who experienced recurrent ischemic strokes in various vascular territories; these strokes were caused by intracranial multiarterial dissection, and were experienced for 2 weeks. She was found to harbor a de novo heterozygous in-frame deletion, c.1333_1335del p.(Thr445del), in exon 4 of the PDE3A gene. Our finding is expected to contribute to the elucidation of the pathophysiology of stroke in HTNB patients. We further review all clinical and molecular genetic features of this rare disease described in the literature to date.

First identified Korean family with Tatton-Brown-Rahman Syndrome caused by the novel DNMT3A variant c.118G>C p.(Glu40Gln).

Tatton-Brown-Rahman Syndrome (TBRS), an overgrowth syndrome caused by heterozygous mutation of DNMT3A, first was described in 2014. Approximately 60 DNMT3A variants, including 32 missense variants, have been reported, with most missense mutations located on the DNMT3A functional domains. Autosomal dominant inheritance by germ-line mutation of DNMT3A has been reported, but vertical transmission within a family is extremely rare. Herein, we report the first Korean family with maternally inherited TBRS due to the novel heterozygous DNMT3A variant c.118G>C p.(Glu40Gln), located outside the main functional domain and identified by multigene panel sequencing. The patient and her mother had typical clinical features, including tall stature during childhood, macrocephaly, intellectual disability, and characteristic facial appearance. TBRS shows milder dysmorphic features than other overgrowth syndromes, potentially leading to underdiagnosis and underestimated prevalence; thus, targeted multigene panel sequencing including DNMT3A will be a useful tool in cases of overgrowth and unexplained mild intellectual disability for early diagnosis and genetic counseling.

Multi-gene panel testing in Korean patients with common genetic generalized epilepsy syndromes.

Genetic heterogeneity of common genetic generalized epilepsy syndromes is frequently considered. The present study conducted a focused analysis of potential candidate or susceptibility genes for common genetic generalized epilepsy syndromes using multi-gene panel testing with next-generation sequencing. This study included patients with juvenile myoclonic epilepsy, juvenile absence epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We identified pathogenic variants according to the American College of Medical Genetics and Genomics guidelines and identified susceptibility variants using case-control association analyses and family analyses for familial cases. A total of 57 patients were enrolled, including 51 sporadic cases and 6 familial cases. Twenty-two pathogenic and likely pathogenic variants of 16 different genes were identified. CACNA1H was the most frequently observed single gene. Variants of voltage-gated Ca2+ channel genes, including CACNA1A, CACNA1G, and CACNA1H were observed in 32% of variants (n = 7/22). Analyses to identify susceptibility variants using case-control association analysis indicated that KCNMA1 c.400G>C was associated with common genetic generalized epilepsy syndromes. Only 1 family (family A) exhibited a candidate pathogenic variant p.(Arg788His) on CACNA1H, as determined via family analyses. This study identified candidate genetic variants in about a quarter of patients (n = 16/57) and an average of 2.8 variants was identified in each patient. The results reinforced the polygenic disorder with very high locus and allelic heterogeneity of common GGE syndromes. Further, voltage-gated Ca2+ channels are suggested as important contributors to common genetic generalized epilepsy syndromes. This study extends our comprehensive understanding of common genetic generalized epilepsy syndromes.

A novel missense mutation in the ACTG1 gene in a family with congenital autosomal dominant deafness: A case report.

The ACTG1 gene encodes the cytoskeletal protein γ-actin, which functions in non­muscle cells and is abundant in the auditory hair cells of the cochlea. Autosomal dominant missense mutations in ACTG1 are associated with DFNA20/26, a disorder that is typically characterized by post­lingual progressive hearing loss. To date, 17 missense mutations in ACTG1 have been reported in 20 families with DFNA20/26. The present study described a small family with autosomal dominant nonsyndromic hearing loss. A novel heterozygous missense mutation, c.94C>T (p.Pro32Ser), in ACTG1 was identified using the TruSight One sequencing panel. Notably, congenital hearing loss in our proband was identified by newborn hearing screening at birth. In silico predictions of protein structure and function indicate that the p.Pro32Ser mutation may result in conformational changes in γ­actin. The present study expands the understanding of the phenotypic effects of heterozygous missense mutations in the ACTG1 gene. In specific, the present results emphasize that mutations in ACTG1 result in a diverse spectrum of onset ages, including congenital in addition to post­lingual onset.

Coinheritance of Novel Mutations in SCN1A Causing GEFS+ and in KDM6A Causing Kabuki Syndrome in a Family.

Because the differentiation between phenotypic expansion and blended phenotypes is not clear, the mixed phenotypes of blended rare genetic diseases make diagnosis difficult. We describe a family with the co-existence and co-segregation of generalized epilepsy with febrile seizures plus (GEFS+) and Kabuki syndrome (KS). The proband, a 7-year-old male, presented with GEFS+, dysmorphic facial features, short stature, developmental delay, and intellectual disability. Two novel missense mutations: p.G325A in the KDM6A gene responsible for KS and p.G1877V in the SCN1A gene responsible for GEFS+ were identified using the TruSight One sequencing panel. This family is the first in the literature to be confirmed molecularly with the blended phenotype of GEFS+ and KS. Furthermore, two affected female patients with X-linked KS showed a partial escape X-inactivation pattern of KDM6A with milder phenotypes than the male affected proband in this study.

Correction: Identification of a Novel Mutation in BRD4 that Causes Autosomal Dominant Syndromic Congenital Cataracts Associated with Other Neuro-Skeletal Anomalies.

[This corrects the article DOI: 10.1371/journal.pone.0169226.].

Identification of a Novel Mutation in BRD4 that Causes Autosomal Dominant Syndromic Congenital Cataracts Associated with Other Neuro-Skeletal Anomalies.

Congenital cataracts can occur as a non-syndromic isolated ocular disease or as a part of genetic syndromes accompanied by a multi-systemic disease. Approximately 50% of all congenital cataract cases have a heterogeneous genetic basis. Here, we describe three generations of a family with an autosomal dominant inheritance pattern and common complex phenotypes, including bilateral congenital cataracts, short stature, macrocephaly, and minor skeletal anomalies. We did not find any chromosomal aberrations or gene copy number abnormalities using conventional genetic tests; accordingly, we conducted whole-exome sequencing (WES) to identify disease-causing genetic alterations in this family. Based on family WES data, we identified a novel BRD4 missense mutation as a candidate causal variant and performed cell-based experiments by ablation of endogenous BRD4 expression in human lens epithelial cells. The protein expression levels of connexin 43, p62, LC3BII, and p53 differed significantly between control cells and cells in which endogenous BRD4 expression was inhibited. We inferred that a BRD4 missense mutation was the likely disease-causing mutation in this family. Our findings may improve the molecular diagnosis of congenital cataracts and support the use of WES to clarify the genetic basis of complex diseases.

Maternally inherited autosomal dominant intellectual disability caused by 16p13.3 microduplication.

A 16p13.3 duplication syndrome has been recently suggested to be a novel recognizable syndrome as a reciprocal microduplication disease of Rubinstein-Taybi syndrome. The CREBBP gene is believed to be the dosage-sensitive critical gene responsible for the reciprocal duplication and deletion syndrome. Descriptions so far have been de novo. Here, we report a very rare case of a maternally inherited a -1 Mb sized duplication on 16p13.3 identified by SNP array testing. The patient showed moderate intellectual disability, normal growth, and characteristic facial features. The patient's mother also had mild intellectual disability, normal growth, camptodactyly, proximally implanted small thumbs, and distinctive facial features. The study provides additional information that furthers the understanding and delineation of 16p13.3 duplication syndrome.

Temple syndrome: A patient with maternal hetero-UPD14, mixed iso- and hetero-disomy detected by SNP microarray typing of patient-father duos.

Temple syndrome (TS, MIM 616222) is an imprinting disorder involving genes within the imprinted region of chromosome 14q32. TS is a genetically complex disorder, which is associated with maternal uniparental disomy of chromosome 14 (UPD14), paternal deletions on chromosome 14, or loss of methylation at the intergenic differentially methylated region (IG-DMR). Here, we describe the case of a patient with maternal hetero-UPD14, mixed iso-/hetero-disomy mechanism identified by a single nucleotide polymorphism (SNP) array analysis of patient-father duos study. The phenotype of our case is similarities to Prader-Willi syndrome (PWS) during infancy and to Russell-Silver syndrome (RSS) during childhood. This SNP array appears to be an effective initial screening tool for patients with nonspecific clinical features suggestive of chromosomal disorders.

Partial trisomy of 11q23.3-q25 inherited from a maternal low-level mosaic unbalanced translocation.

Partial trisomy of 11q is characterized by pre/postnatal growth retardation, microcephaly, dysmorphic craniofacial features, cognitive disability, abnormal muscle tone, inguinal hernia, and possible congenital heart defects. Here, we describe a 17-year-old male with a 17.77 Mb-sized [arr 11q23.3-q25 (116,667,559 -134,434,130) ×3] partial trisomy resulting from the unbalanced translocation between chromosomes 11 and 22. The terminal translocation was detected using oligonucleotide array comparative genomic hybridization (CGH) with fluorescence in situ hybridization (FISH) confirmation. The partial trisomy was inherited from his mother who had the low-level (22.7%) mosaic unbalanced translocation and a normal phenotype. The patient showed most of the common features of partial trisomy 11q syndrome, with additional findings, including mesenteric fibromatosis.

A 13-year-old boy with a 7q36.1q36.3 deletion with additional findings.

Relatively little is known about 7q terminal deletion contiguous gene deletion syndrome. The deleted region includes more than 40 OMIM genes. We here report on a 13-year-old boy with 7q terminal deletion syndrome, a 6.89-Mb sized deletion on 7q36.1q36.3, identified by oligonucleotide array comparative genomic hybridization (CGH). He showed microform holoprosencephaly with microcephaly, distinctive facial features, severe intellectual disabilities, behavior problems, seizures, short stature, penoscrotal transposition, and ulnar ray deficiency. To date, no case of penoscrotal transposition or ulnar ray deficiency has been reported in 7q terminal syndrome. The majority of our patient presentations were attributed to dosage expression of the SHH gene with contributions from deleted genes within 7q.

The natural course of clinically isolated syndrome in pediatric patients.

BACKGROUND: The first episode of central nervous system (CNS) symptoms with a presumed inflammatory demyelinating cause is defined as clinically isolated syndrome (CIS) according to the 2007 consensus of the International Pediatric Multiple Sclerosis Study Group, which developed diagnostic criteria for CNS demyelination disease in children. Using this definition of CIS, we attempted to identify the natural course of pediatric patients with CIS in a single Korean institution and to determine the factors affecting their prognosis. METHODS: We retrospectively reviewed the medical records of all pediatric patients (age <18 years old) who presented with clinical symptoms of CNS events between 1997 and 2008. RESULTS: We identified 32 patients with CIS. Their mean age with standard deviation was 10.0±4.1 years. The most common type of presentation of CIS was optic neuritis (ON). Sixteen (16/32, 50%) patients experienced a second demyelinating event. The mean interval between the first event and the recurrent episode was 21±20 months. The mean follow-up was 6.1±1.6 years. Eleven (34%) patients developed childhood onset multiple sclerosis (MS). In contrast to previous studies, asymptomatic brain lesions on magnetic resonance imaging (MRI) and the presence of cerebrospinal fluid (CSF) oligoclonal bands (OCBs) were not predictors of conversion to MS. CONCLUSION: In our study, a second relapse and initial presentation with brain stem, cerebellar, cerebral dysfunction, or multifocal CIS were strongly associated with the development of MS (p=0.002). Despite clinical definitions and increased understanding of CIS in children, challenges remain in predicting its progression to a chronic demyelinating disease.

Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea.

PURPOSE: Acute necrotizing encephalopathy (ANE) is a fulminant disease of the brain characterized by bilateral thalamic lesions, and is prevalent among children in East Asia. The prognosis of ANE is usually poor with a high mortality rate and neurological sequelae. This study aimed to delineate the clinical characteristics and prognostic factors of ANE. METHODS: We retrospectively analyzed clinical data of 399 pediatric patients with encephalitis who were admitted to Samsung Medical Center from December 1998 to March 2011. We enrolled ten patients (11 cases) with ANE and analyzed their demographic, clinical, and neuroimaging data. The location and extent of the brain regions were checked based on fluid-attenuated inversion recovery, T1-, and T2-weighted imaging findings; the presence of contrast enhancement, restricted diffusion, and hemorrhage. RESULTS: Ten patients were identified, including one patient with two episodes. The median age of onset was 1.5 years (0.4-8.4 years). The mortality rate was 40%, and only 30% of patients survived without neurological sequelae. The definite involvement of the brainstem on brain magnetic resonance imaging was significantly correlated with mortality (P=0.04). CONCLUSION: Broad and extensive brainstem involvement suggested the fulminant course of ANE. Early diagnosis of ANE before brainstem involvement, through careful identification of symptoms of brain dysfunction, may be the best way to achieve better neurological outcomes.

Array-based comparative genomic hybridization in 190 Korean patients with developmental delay and/or intellectual disability: a single tertiary care university center study.

PURPOSE: This study analyzed and evaluated the demographic, clinical, and cytogenetic data [G-banded karyotyping and array-based comparative genomic hybridization (array CGH)] of patients with unexplained developmental delay or intellectual disability at a single Korean institution. MATERIALS AND METHODS: We collected clinical and cytogenetic data based on retrospective charts at Ajou University Medical Center, Suwon, Korea from April 2008 to March 2012. RESULTS: A total of 190 patients were identified. Mean age was 5.1±1.87 years. Array CGH yielded abnormal results in 26 of 190 patients (13.7%). Copy number losses were about two-fold more frequent than gains. A total of 61.5% of all patients had copy number losses. The most common deletion disorders included 22q11.2 deletion syndrome, 15q11.2q12 deletion and 18q deletion syndrome. Copy number gains were identified in 34.6% of patients, and common diseases among these included Potocki-Lupski syndrome, 15q11-13 duplication syndrome and duplication 22q. Abnormal karyotype with normal array CGH results was exhibited in 2.6% of patients; theses included balanced translocation (n=2), inversion (n=2) and low-level mosaicism (n=1). Facial abnormalities (p<0.001) and failure to thrive were (p<0.001) also more frequent in the group of patients with abnormal CGH findings. CONCLUSION: Array CGH is a useful diagnostic tool in clinical settings in patients with developmental delay or intellectual disability combined with facial abnormalities or failure to thrive.