Natural History and Molecular Characteristics of Korean Patients with Mucopolysaccharidosis Type III

Background: Mucopolysaccharidosis type III (MPS III) is an autosomal recessive lysosomal storage disorder characterised by progressive neurocognitive deterioration. MPS III subtypes are clinically indistinguishable, with a wide range of symptoms and variable severity. The natural history of this disorder within an Asian population has not yet been extensively studied. This study investigated the natural history of Korean patients with MPS III. Methods: Thirty-four patients from 31 families diagnosed with MPS III from January 1997 to May 2020 in Samsung Medical Centre were enrolled. Clinical, molecular, and biochemical characteristics were retrospectively collected from the patients’ medical records and via interviews. Results: 18 patients had MPS IIIA, 14 had IIIB, and two had IIIC. Twenty (58.9%) patients were male. Mean age at symptom onset was 2.8 ± 0.8 years and at diagnosis was 6.3 ± 2.2 years. All patients with MPS IIIA and IIIB were classified into the rapidly progressing (RP) phenotype. The most common symptom at diagnosis was language retardation (88.2%), followed by motor retardation (76.5%), general retardation (64.7%), and hyperactivity (41.2%). Language retardation was more predominant in IIIA, and motor retardation was more predominant in IIIB. The mean age of the 13 deceased patients at the time of the study was 14.4 ± 4.1 years. The age at diagnosis and lag time were significantly older and longer in the non-survivor group compared with the survivor group (p = 0.029 and 0.045, respectively). Genetic analysis was performed in 24 patients with MPS III and identified seven novel variants and three hot spots. Conclusion: This study is the first to analyse the genetic and clinical characteristics of MPS III patients in Korea. Better understanding of the natural history of MPS III might allow early diagnosis and timely management of the disease and evaluation of treatment outcomes in future clinical trials for MPS III.

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.

The First Korean Family with Aarskog-Scott Syndrome Harboring a Novel Mutation in FGD1 Diagnosed via Targeted Gene Panel Sequencing

Aarskog-Scott syndrome (AAS), also known as faciogenital dysplasia (FGD, OMIM # 305400), is an X-linked recessive inheritance, characterized by short stature, facial dysmorphism, and skeletal abnormalities. We report the clinical and molecular analysis of a family with ASS. A 31-month-old boy and his cousin were initially mistaken for having Noonan syndrome owing to short stature and facial dysmorphism. Considering the family history, we suspected the possibility of an X-linked genetic disease and performed targeted gene panel sequencing; a novel hemizygous variant c.1192-1 G>A in FGD1 was identified in both the proband and his cousin. This is the first report of ASS in Korea. Targeted gene panel sequencing can be an effective tool for diagnosing rare complex syndromes, including ASS.

Carcinoma erysipeloides associated with anaplastic thyroid carcinoma

Cutaneous metastases from carcinoma of the thyroid gland are rare and carcinoma erysipeloides is even rarer. We present the clinical, histological, and immunohistochemical features of inflammatory erysipeloid metastases arising from an anaplastic carcinoma of the thyroid gland. In this case the anaplastic carcinoma probably transformed from a pre-existing, long-standing papillary carcinoma of the thyroid gland. Although visible inflammation is a hallmark of many benign skin disorders, it is not commonly present in cutaneous malignant metastases. As a result, the significance of a marked inflammatory changes in association with metastatic skin disease may not be recognized. Dermatologists need to be aware of the potential for inflammatory manifestations in cutaneous metastases from a thyroid carcinoma.