First female Korean child with Coffin-Lowry syndrome: a novel variant in RPS6KA3 diagnosed by exome sequencing and a literature review.

Coffin-Lowry syndrome (CLS, OMIM # 303600) is a rare X-linked disorder caused by mutations in RPS6KA3. CLS is characterized by facial dysmorphism, digit abnormalities, developmental delays, growth retardation, and progressive skeletal changes in male patients. Females with CLS are variably affected, complicating diagnosis. Here, we describe the clinical and molecular findings in a female Korean child with CLS and review the associated literature. A 5-year-old girl presented with short stature and developmental delays. She had a coarse facial appearance characterized by a prominent forehead, hypertelorism, thick lips, and hypodontia. She also had puffy tapering fingers and pectus excavatum. We performed exome sequencing and identified a novel, likely pathogenic, heterozygous variant, c.326_338delinsCTCGAGAC (p.Val109Alafs*10), in RPS6KA3 (NM_004586.2). This is the first Korean female genetically diagnosed with CLS. In contrast to the delayed bone age reported in previous studies, our patient showed advanced bone age and central precocious puberty. CLS should be considered as a differential diagnosis of short stature, tapering fingers, and developmental delay. We suggest that molecular techniques can be a useful tool for diagnosis of rare disorders such as CLS because such conditions are not simple, and the associated spectrum of phenotypes can vary.

Wilson disease diagnosed incidentally by targeted gene panel sequencing in a Korean boy with severe obesity.

Wilson disease (WD) is a relatively common genetic hepatic disease in children and is characterized by excessive copper accumulation, predominantly in the liver and brain. It is an autosomal recessive disease caused by an ATP7B mutation that causes brain degeneration and is potentially fatal if diagnosed late or untreated. In the early phase of WD, its initial presentation may include mild hepatic involvement. WD may be overlooked as a cause of liver disease due to severe obesity but should not be excluded from differential diagnosis. We report a case of WD with severe obesity and fatty liver diagnosed in the early phase by targeted gene panel sequencing and review the endocrine problems associated with WD. Early suspicion of WD is important for good prognosis.

Long-Term Antithyroid Drug Treatment of Graves' Disease in Children and Adolescents: A 20-Year Single-Center Experience.

Background/purpose: Graves' disease (GD) is the most common cause of thyrotoxicosis in children and adolescents. There is some debate regarding the optimal treatment and predicting factors of remission or relapse in children and adolescents with GD. In this study, we report a retrospective study of 195 children and adolescents with GD treated at a single tertiary institution in Korea. Methods: This study included children and adolescents with GD diagnosed before 19 years of age from January of 2000 to October of 2020. The diagnosis of GD was based on clinical features, high thyroxine (FT4), suppressed thyroid-stimulating hormone, and a positive titer of thyrotropin receptor antibodies. Remission was defined as maintenance of euthyroid status for more than six months after discontinuing antithyroid drug (ATD). Results: A total of 195 patients with GD were included in this study. The mean age at diagnosis was 12.9 ± 3.2 years, and 162 patients (83.1%) were female. Among all 195 patients, five underwent thyroidectomy and three underwent radioactive iodine therapy. The mean duration of follow-up and ATD treatment were 5.9 ± 3.8 years and 4.7 ± 3.4 years, respectively. The cumulative remission rates were 3.3%, 19.6%, 34.1%, 43.5%, and 50.6% within 1, 3, 5, 7, and 10 years of starting ATD, respectively. FT4 level at diagnosis (P = 0.001) was predicting factors for remission [HR, 0.717 (95% CI, 0.591 - 0.870), P = 0.001]. Methimazole (MMI)-related adverse events (AEs) occurred in 11.3% of patients, the most common of which were rash and hematologic abnormalities. Of a total of 26 AEs, 19 (73.1%) occurred within the first month of taking MMI. Conclusions: In this study, the cumulative remission rate increased according to the ATD treatment duration. Long-term MMI treatment is a useful treatment option before definite treatment in children and adolescents with GD.

Natural course and prognostic factors of chronic urticaria in Korean children: A single center experience.

BACKGROUND: Chronic urticaria (CU) has an adverse effect on academic achievement and psychosocial development in children. OBJECTIVE: We aimed to investigate the natural course of CU and to identify relevant factors associated with a poor CU prognosis in Korean children. METHODS: We retrospectively analyzed 253 children with episodes of wheals or angioedema at least 3 times a week that persisted for at least 6 weeks. Clinical data and laboratory results were obtained from medical records and parental telephone interviews. Kaplan-Meier survival analysis and log rank tests were performed to assess the median time to remission of CU and prognostic factors. RESULTS: Median age at onset was 5.0 years (interquartile range, 2.5-9.1) and median follow-up period was 7.6 months (interquartile range, 3.9-19.7). Of 253 patients, 68.8% had chronic inducible urticaria and 31.2% had chronic spontaneous urticaria. Physical urticaria was the only cause of chronic inducible urticaria, and the most common physical urticaria was dermographism. Median duration to remission of CU was 10.2 months (95% confidence intervals, 8.0-12.5 months). Kaplan-Meier analysis revealed that 33.4%, 53.0%, and 71.2% of children were in remission at 6, 12, and 24 months, respectively, after the onset of CU. The presence of allergic sensitization was significantly associated with a poor CU prognosis in univariable and multivariable analyses (P=0.010 and P=0.014, respectively). CONCLUSION: Half of children with CU were in remission 10.2 months after onset. Allergic sensitization was a risk factor associated with longer duration CU.

Clinical and molecular characterization of Korean children with infantile and late-onset Pompe disease: 10 years of experience with enzyme replacement therapy at a single center.

PURPOSE: Pompe disease (PD) is an autosomal recessive disorder caused by a deficiency of acid alphaglucosidase resulting from pathogenic GAA variants. This study describes the clinical features, genotypes, changes before and after enzyme replacement therapy (ERT), and long-term outcomes in patients with infantile-onset PD (IOPD) and late-onset PD (LOPD) at a tertiary medical center. METHODS: The medical records of 5 Korean patients (2 male, 3 female patients) diagnosed with PD between 2002 and 2013 at Samsung Medical Center in Seoul, Republic of Korea were retrospectively reviewed for data, including clinical and genetic characteristics at diagnosis and clinical course after ERT. RESULTS: Common initial symptoms included hypotonia, cyanosis, and tachycardia in patients with IOPD and limb girdle weakness in patients with LOPD. Electrocardiography at diagnosis revealed hypertrophic cardiomyopathy in all patients with IOPD who showed a stable disease course during a median follow-up period of 10 years. Patients with LOPD showed improved hepatomegaly and liver transaminase level after ERT. CONCLUSION: As ERT is effective for treatment of PD, early identification of this disease is very important. Thus, patients with IOPD should be considered candidates for clinical trials of new drugs in the future.

Oculodentodigital Dysplasia with a Novel Mutation in GJA1 Diagnosed by Targeted Gene Panel Sequencing: A Case Report and Literature Review.

Oculodentodigital dysplasia (ODDD; MIM #164200), a rare genetic disorder characterized by abnormal craniofacial, dental, ocular, and digital features, is caused by mutations in the gap junction alpha-1 (GJA1) gene. We report a case of a 6-year-old male who presented with dysmorphic facial features (short palpebral fissure, thin nose with hypoplastic alae nasi, and flat face), bilateral syndactyly, abnormal dentition, and proportionate short stature with growth hormone deficiency. A novel de novo heterozygous missense mutation (c.221A>C, p.H74P) in GJA1 was identified by targeted gene panel sequencing. This is the first case report of a novel ODDD-causing mutation in GJA1 confirmed by genetic analysis in Korea.