Impact of Nontreatment Duration and Keratopathy on Major Adverse Cardiovascular Events in Fabry Disease: A Nationwide Cohort Study.

Fabry disease (FD) is a rare inherited X-linked lysosomal storage disorder that results in the progressive accumulation of glycosphingolipids in multiple organs. Early FD-specific treatments may improve clinical outcomes; however, clinical evidence about early FD treatment is limited. We aimed to determine the cardiovascular outcomes of patients with FD who received enzyme replacement therapy. This nationwide observational study was conducted using the National Health Claims database of the Korean population with FD. The primary outcome was major adverse cardiovascular events (MACEs). MACE risk factors in FD were evaluated using time-dependent Cox regression. Between January 2007 and April 2022, 188 patients with FD were analyzed. Among them, 22 (11.7%) experienced MACE (males: 14/95 [14.7%]; females: 8/93 [8.6%]). The mean age at MACE diagnosis was 53.5 ± 11.0 years in all patients with FD, which was lower in males compared with in females (49.7 ± 9.6 vs. 60.0 ± 10.7 years, p = 0.030). Multivariate analysis (HR, 95% CI) revealed that age (1.042; 1.004-1.082) and duration of FD nontreatment (1.040; 1.003-1.078) were significant MACE risk factors in all patients. In males, age (1.080; 1.032-1.131), FD nontreatment duration (1.099; 1.048-1.152), and keratopathy (18.920; 4.174-85.749) were significant MACE risk factors in multivariate analysis. In females, the only significant MACE risk factor was a high Charlson comorbidity index score (1.795; 1.229-2.622). In conclusion, duration of FD nontreatment and keratopathy are significant MACE risk factors in males with FD. These findings suggest the importance of early initiation of FD-specific treatment and careful evaluation of keratopathy in males with FD.

2022 Clinical practice guidelines for central precocious puberty of Korean children and adolescents.

The Committee of Central Precocious Puberty of Korean Pediatrics and Adolescents of the Korean Society of Pediatric Endocrinology has newly developed evidence-based 2022 clinical practice guidelines for central precocious puberty in Korean children and adolescents. These guidelines provide the grade of recommendations, which includes both the strength of recommendations and the level of evidence. In the absence of sufficient evidence, recommendations are based on expert opinion. These guidelines have been revised and supplement the previous guidelines "Clinical Guidelines for Precocious Puberty 2011," and are drawn from a comprehensive review of the latest domestic and international research and the grade of recommendation appropriate to the domestic situation. This review summarizes the newly revised guidelines into 8 key questions and 27 recommendations and consists of 4 sections: screening, diagnosis, treatment, and long-term outcome of central precocious puberty.

DHX30-Associated Neurodevelopmental Disorder with Severe Motor Impairment and Absent Language: First Korean Case in Two Siblings and Literature Review.

DHX30 variants have recently been reported in patients with neurodevelopmental disorders with severe motor impairment and absent language (NEDMIAL). We report the first Korean siblings presenting with NEDMIAL and previously unreported clinical features harboring a rare de novo DHX30 missense variant. The proband was a 10-year-old boy presenting with intellectual disability with severe motor impairment, absent language, facial dysmorphism, strabismus, sleep disturbances, and feeding difficulties. We performed whole-exome sequencing using genomic deoxyribonucleic acid isolated from buccal swabs, which revealed a heterozygous missense variant of DHX30: (c.2344C>T, p.Arg782Trp). Sanger sequencing was conducted for the proband, the affected sister, and each parent. The same variant was confirmed in two siblings but not in their parents, suggesting the possibility of de novo germline mosaicism.

Impact of 6-month triptorelin formulation on predicted adult height and basal gonadotropin levels in patients with central precocious puberty.

Background: Triptorelin, a long-acting gonadotropin-releasing hormone (GnRH) agonist, is available in 1-, 3-, and 6-month formulations to treat central precocious puberty (CPP). The triptorelin pamoate 22.5-mg 6-month formulation recently approved for CPP offers greater convenience to children by reducing the injection frequency. However, worldwide research on using the 6-month formulation to treat CPP is scarce. This study aimed to determine the impact of the 6-month formulation on predicted adult height (PAH), changes in gonadotropin levels, and related variables. Methods: We included 42 patients (33 girls and nine boys) with idiopathic CPP treated with a 6-month triptorelin (6-mo TP) formulation for over 12 months. Auxological parameters, including chronological age, bone age, height (cm and standard deviation score [SDS]), weight (kg and SDS), target height (TH), and Tanner stage, were evaluated at baseline, and after 6, 12, and 18 months of treatment. Hormonal parameters, including serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol for girls or testosterone for boys, were analyzed concurrently. Results: The mean age at treatment initiation was 8.6 ± 0.83 (8.3 ± 0.62 for girls, 9.6 ± 0.68 for boys). The peak LH level following intravenous GnRH stimulation at diagnosis was 15.47 ± 9.94 IU/L. No progression of the modified Tanner stage was observed during treatment. Compared to baseline, LH, FSH, estradiol, and testosterone were significantly reduced. In particular, the basal LH levels were well suppressed to less than l.0 IU/L, and the LH/FSH ratio was less than 0.66. The bone age/chronological age ratio remained stable with a decreasing trend (1.15 at the start of treatment, 1.13 at 12 months, 1.11 at 18 months). PAH SDS increased during treatment (0.77 ± 0.79 at baseline, 0.87 ± 0.84 at the start of treatment, 1.01 ± 0.93 at six months, and 0.91 ± 0.79 at 12 months). No adverse effects were observed during treatment. Conclusion: The 6-mo TP suppressed the pituitary-gonadal axis stably and improved the PAH during treatment. Considering its convenience and effectiveness, a significant shift to long-acting formulations can be expected.

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.

Association Between Non-invasive Diagnostic Methods of Liver Fibrosis and Type 2 Diabetes in Pediatric Patients With Non-alcoholic Fatty Liver Disease.

BACKGROUND AND PURPOSE: The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has been increasing associated with insulin resistance. However, there is a scarcity of related studies in children with NAFLD with type 2 diabetes mellitus (T2DM) compared to adults. We conducted this study to investigate the association between non-invasive diagnostic methods of liver fibrosis and T2DM in pediatric patients with NAFLD. METHODS: We enrolled a total of 152 patients aged <18 years with NAFLD, and compared their data according to the presence of T2DM. We evaluated fibrosis by transient elastography (TE, FibroScan®), and calculated the following fibrosis scores for each patient: NAFLD fibrosis score (NFS), AST: platelet ratio index (APRI), Fibrosis-4 (FIB-4) index, and pediatric NAFLD fibrosis index (PNFI). RESULTS: In the NAFLD-T2DM group, the NFS and mean controlled attenuation parameter in FibroScan were significantly higher than those in the nondiabetic group. The receiver operating characteristic (ROC) curve values for predicting the presence of T2DM were 0.78 for NFS, 0.64 for FIB-4, 0.62 for PNFI, and 0.61 for APRI. The cutoff HbA1c levels for predicting fibrosis progression in APRI, NFS, and PNFI were 5.7% [area under the curve (AUC) 0.74], 6.4% (AUC 0.71), and 6.4% (AUC 0.55), respectively. In the multivariate analysis, hepatosteatosis on abdomen sonography, NFS, FibroScan F, and APRI were independently associated with T2DM risk. CONCLUSIONS: We significantly characterized non-invasive fibrosis markers and elastography in pediatric NAFLD with T2DM compared with the nondiabetic group. We suggest evaluating the progression of fibrosis in the prediabetic stage in children using a combination of these non-invasive methods.

Development and validation of the Pediatric-Youth Hyperphagia Assessment for Prader-Willi syndrome.

OBJECTIVES: Hyperphagia is a highly stressful, life-threatening feature of Prader-Willi syndrome (PWS). It is important to assess this complex behavior accurately over time. This study aimed to develop and validate the Pediatric-Youth Hyperphagia Assessment for Prader-Willi syndrome (PYHAP) as a tool targeting children and adolescents. METHODS: After an extensive literature review and qualitative interviews, the final version of the PYHAP with 14 questions in 3 domains (verbal [5], behavior [4], and social [5]) was developed and tested at Samsung Medical Center in Seoul, Korea from July 2018 to September 2019. Exploratory factor analysis and confirmatory factor analysis (CFA) were performed to confirm construct validity. The correlations between the PYHAP and the Korean Children's Eating Behavior Questionnaire (K-CEBQ) were calculated to evaluate convergent and discriminant validity. Criterion validity and the validity of the response categories were also tested. RESULTS: Cronbach's alpha coefficient of the PYHAP was 0.91. The fit indices for CFA were good (comparative fit index, 0.87; standardized root mean squared residual, 0.08). The domains of the PYHAP were closely correlated with the relevant domains of the K-CEBQ. The accuracy of the PYHAP score for predicting uncontrolled hyperphagia was good (area under the curve, 0.75; 95% confidence interval, 0.65 to 0.85). CONCLUSIONS: The PYHAP was confirmed to be a reliable and valid tool to evaluate hyperphagia in children and adolescents with PWS via caregivers' assessments. It is recommended to use the PYHAP to communicate with parents or caregivers about patients' hyperphagia or to monitor and manage extreme behaviors in children with PWS.

Identification of a novel KAT6A variant in an infant presenting with facial dysmorphism and developmental delay: a case report and literature review.

BACKGROUND: Arboleda-Tham syndrome (ARTHS), caused by a pathogenic variant of KAT6A, is an autosomal dominant inherited genetic disorder characterized by various degrees of developmental delay, dysmorphic facial appearance, cardiac anomalies, and gastrointestinal problems. CASE PRESENTATION: A baby presented multiple facial deformities including a high arched and cleft palate, with philtral ridge and vermilion indentation, a prominent nasal bridge, a thin upper lip, low-set ears, an epicanthal fold, and cardiac malformations. Whole exome sequencing (WES) revealed a heterozygous nonsense mutation in exon 8 of the KAT6A gene (c.1312C>T, p.[Arg438*]) at 2 months of age. After a diagnosis of ARTHS, an expressive language delay was observed during serial assessments of developmental milestones. CONCLUSIONS: In this study, we describe a case with a novel KAT6A variant first identified in Korea. This case broadens the scope of clinical features of ARTHS and emphasizes that WES is necessary for early diagnosis in patients with dysmorphic facial appearances, developmental delay, and other congenital abnormalities.

The role of growth hormone device optimization in patient-reported outcomes: real-world evidence from South Korea.

BACKGROUND: Growth hormone (GH) treatment preference and adherence are affected by delivery device convenience, injection-site pain, confidence in correct dose administration, and device satisfaction. This survey investigated if switching device to NordiFlex® improved treatment experience in pediatric patients in South Korea. DESIGN AND METHODS: Patients aged 4-≤18 years were surveyed. Participants were NordiFlex® users who previously used NordiLet®/other devices. Participants compared preference, self-reported adherence, satisfaction, perceived ease of use, and device subjective benefits (across four domains: ease of use, self-efficacy, minimal disruption of daily life, positive feelings about injections) of NordiFlex® vs. previous device. RESULTS: Ninety-four patients were enrolled, of which 91.5% previously used NordiLet®. Significantly more patients preferred, and were more satisfied with NordiFlex® vs. previous device; mean score: 0.65 (95% confidence interval [CI]:0.41;0.88) and 0.61 (95% CI:0.36;0.85), respectively. Participants reported greater perceived ease of use (0.49 [95% CI:0.26;0.72]) and fewer missed injections (0.20 [95% CI:0.06;0.34], with NordiFlex® vs. previous device. Bivariate analysis showed significant associations between preference for NordiFlex® and higher scores on self-efficacy, ease of use, minimal disruption of daily life, and positive feelings about injection (all p < 0.001). CONCLUSION: These results suggest that improvements in device features could be associated with improved treatment experience.

Two Novel Mutations of ANKRD11 Gene and Wide Clinical Spectrum in KBG Syndrome: Case Reports and Literature Review.

BACKGROUND: KBG syndrome (OMIM #148050) is a rare, autosomal dominant inherited genetic disorder caused by heterozygous mutations in the ankyrin repeat domain-containing protein 11 (ANKRD11) gene or by microdeletion of chromosome 16q24.3. It is characterized by macrodontia of the upper central incisors, distinctive facial dysmorphism, short stature, vertebral abnormalities, hand anomaly including clinodactyly, and various degrees of developmental delay. KBG syndrome presents with variable clinical feature and severity among individuals. Here, we report two KBG patients who have different novel heterozygous mutations of ANKRD11 gene with wide range of clinical manifestations. CASE PRESENTATION: Two novel heterozygous mutations of ANKRD11 gene were identified in two unrelated Korean patients with variable clinical presentations. The first patient presented with short stature and early puberty and was treated with growth hormone and gonadotropin-releasing hormone agonist without adverse effects. He had mild intellectual disability. In targeted exome sequencing, a novel de novo frameshift variant was identified in ANKRD11, c.5889del, and p. (Ile1963MetfsX9). The second patient had severe intellectual disability with epilepsy. He had normal height and prepubertal stage at the age of 11 years. He had behavioral problems such as autism-like features, anxiety, and stereotypical movements. Whole exome sequencing (WES) was performed, and the novel heterozygous mutation, c3310dup, p. (Glu110GlyfsTer5) in ANKRD11 was identified. CONCLUSION: KBG syndrome is often underdiagnosed because of its non-specific features and phenotypic variability. Performing a next-generation sequencing panel, including the ANKRD11 gene for cases of developmental delay with/without short stature may be helpful to identify hitherto undiagnosed KBG syndrome patients.

Multisystem Inflammatory Syndrome in Children Related to COVID-19: the First Case in Korea.

Since mid-April 2020, cases of multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 that mimics Kawasaki disease (KD) have been reported in Europe and North America. However, no cases have been reported in Korea. We describe an 11-year old boy with fever, abdominal pain, and diarrhea who developed hypotension requiring inotropes in intensive care unit. His blood test revealed elevated inflammatory markers, thrombocytopenia, hypoalbuminemia, and coagulopathy. Afterward, he developed signs of KD such as conjunctival injection, strawberry tongue, cracked lip, and coronary artery dilatation, and parenchymal consolidation without respiratory symptoms. Microbiological tests were all negative including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction. However, serum immunoglobulin G against SARS-CoV-2 was positive in repeated tests using enzyme-linked immunosorbent assay and fluorescent immunoassay. He was recovered well after intravenous immunoglobulin administration and discharged without complication on hospital day 13. We report the first Korean child who met all the criteria of MIS-C with features of incomplete KD or KD shock syndrome.

Coexistence of Growth Hormone Deficiency and Pituitary Microadenoma in a Child with Unique Mosaic Turner Syndrome: A Case Report and Literature Review.

Turner syndrome (TS) is a genetic disorder with phenotypic heterogeneity caused by the monosomy or structural abnormalities of the X chromosome, and it has a prevalence of about 1/2500 females live birth. The variable clinical features of TS include short stature, gonadal failure, and skeletal dysplasia. The association with growth hormone (GH) deficiency or other hypopituitarism in TS is extremely rare, with only a few case reports published in the literature. Here, we report the first case of a patient with mosaic TS with complete GH deficiency and pituitary microadenoma, and we include the literature review. During the work-up of the patient for severe short stature, three GH provocation tests revealed peak GH levels of less than 5 ng/mL, which was compatible with complete GH deficiency. Sella magnetic resonance imaging showed an 8 mm non-enhancing pituitary adenoma with mild superior displacement of the optic chiasm. Karyotyping revealed the presence of ring chromosome X and monosomy X (46,X,r(X)/45,X/46,X,psu dic r(X;X)), which indicated a mosaic TS. It is important to consider not only chromosome analyses in females with short stature, but also the possibility of the coexistence of complete GH deficiency accompanying pituitary lesions in TS. In conclusion, the present study reports the first case of GH deficiency and pituitary adenoma in a patient with rare mosaic TS, which extends the genotype-phenotype spectrum for TS.

Clinical, Hormonal, and Neuroradiological Characteristics and Therapeutic Outcomes of Prolactinomas in Children and Adolescents at a Single Center.

Background/Purpose: A prolactinoma is the most common pituitary adenoma, but it is relatively rare in childhood and adolescence. There is only limited research about the clinical spectrum, treatment, and outcomes of prolactinomas in childhood and adolescence. In this single-center cohort study, we assessed the clinical, hormonal, and neuroradiological characteristics and therapeutic outcomes of children and adolescents with prolactinomas. Methods: This retrospective cohort study included 25 patients with prolactinomas diagnosed before 19 years of age, who presented at Samsung Medical Center during a 15-year period (March 2005 to August 2019). Results: The median age at diagnosis was 16.9 (range 10.1-18.5) years, and 80% of the patients were female. The common clinical manifestations at diagnosis were galactorrhea (10/20, 50%) and amenorrhea (9/20, 45%) among females and visual field defects (3/5, 60%) and headaches (2/5, 40%) among males. In our cohort, macroadenomas accounted for 56% of cases, and the rate of overall responsiveness to dopamine agonists (DAs) was 56% (10/18). Male gender, the prolactin (PRL) level at diagnosis, and the presence of panhypopituitarism were positively correlated with maximum tumor diameter (r = 0.443, P = 0.026; r = 0.710, P < 0.001; and r = 0.623, P = 0.001, respectively). After the trans-sphenoidal approach (TSA), 53% (8/15) of patients showed normalization of the PRL level. Three patients, who underwent gamma knife surgery (GKS) owing to either resistance or intolerance to DAs or recurrence after the TSA, achieved a normal PRL level accompanied with marked tumor reduction and symptom remission. Conclusions: A macroprolactinoma is more prevalent than a microprolactinoma in children and adolescents than in adults. Male gender, increased PRL levels, and the presence of panhypopituitarism at diagnosis are closely related to macroprolactinomas in children and adolescents.

Impact of BMI on peak growth hormone responses to provocative tests and therapeutic outcome in children with growth hormone deficiency.

This study investigated the relationship between peak stimulated growth hormone (GH) and body mass index (BMI), as well as the impact of BMI on therapeutic response in patients with GH deficiency (GHD). A total of 460 patients were enrolled in the study. The patients were divided into four groups as per the etiology and peak GH values: idiopathic (n = 439), organic (n = 21), complete (n = 114), and partial (n = 325) GHD groups. Subsequently, they were classified as normal, overweight, or obese based on their BMI. There was no difference in BMI between complete and partial GHD. A significant negative relationship between peak GH and BMI were found. Moreover, obese GHD children had a considerably better therapeutic response in height increase and BMI decrease during 2 years of GH treatment compared to non-obese children with GHD. There was no difference between peak GH and type of GH stimulation test (GHST), except the clonidine test, which showed a much lower peak GH in obese GHD children. In conclusion, BMI had a negative impact on peak GH response, and therapeutic outcome was more favorable in the obese group. Despite no difference in GH response by type of GHST, the degree of obesity differentially affected the results.

Long-term follow-up on MURCS (Müllerian duct, renal, cervical somite dysplasia) association and a review of the literature.

Müllerian duct aplasia-renal aplasia-cervicothoracic somite dysplasia (MURCS) association is a unique development disorder with four common types of malformations that include uterine aplasia or hypoplasia, renal ectopy or agenesis, vertebral anomalies, and short stature. The majority of MURCS patients are diagnosed with primary amenorrhea from late-adolescence. However, a few cases with MURCS association are not well diagnosed during childhood and long-term outcomes are not well reported. We report a case of an 8-year-old girl with MURCS association who presented with recurrent urinary tract infections and multiple congenital malformations, and who was followed for 10 years until adulthood. MURCS association should be considered as one of the differential diagnoses when evaluating prepubertal females with vertebral and renal malformations.

Effects of recombinant human growth hormone treatment on growth, body composition, and safety in infants or toddlers with Prader-Willi syndrome: a randomized, active-controlled trial.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare complex genetic disorder and is characterized by short stature, muscular hypotonia, abnormal body composition, psychomotor retardation, and hyperphagia. Recombinant human growth hormone (rhGH) treatment improves the symptoms in children with PWS, and early treatment results in more favorable outcomes. However, systematic studies in infants and toddlers under 2 years of age are lacking. This multicenter, randomized, active-controlled, parallel-group, open-label, Phase III study aimed to evaluate the safety of rhGH (Eutropin, LG Chem, Ltd.) and its efficacy on growth, body composition, and motor and cognitive development in infants and toddlers with PWS compared with a comparator treatment (Genotropin, Pfizer, Inc.). Eligible Korean infants or toddlers with PWS were randomly assigned to receive Eutropin or comparator (both 0.24 mg/kg/week, 6 times/week) for 1 year. Height standard deviation score (SDS), body composition, and motor and cognitive development were measured. RESULTS: Thirty-four subjects (less than 24 months old) were randomized into either the Eutropin (N = 17) group or the comparator (N = 17) group. After 52 weeks of rhGH treatment, height SDS and lean body mass increased significantly from baseline in both groups: the mean height SDS change (SD) was 0.75 (0.59) in the Eutropin group and 0.95 (0.66) in the comparator group, and the mean lean body mass change (SD) was 2377.79 (536.25) g in the Eutropin group and 2607.10 (641.36) g in the comparator group. In addition, percent body fat decreased significantly: the mean (SD) change from baseline was - 8.12% (9.86%) in the Eutropin group and - 7.48% (10.26%) in the comparator group. Motor and cognitive developments were also improved in both groups after the 1-year treatment. The incidence of adverse events was similar between the groups. CONCLUSIONS: rhGH treatment for 52 weeks in infants and toddlers with PWS improved growth, body composition, and motor and cognitive development, and efficacy and safety outcomes of Eutropin were comparable to those of Genotropin. Hence, Eutropin is expected to provide safe and clinically meaningful improvements in pediatric patients with PWS. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (identifier: NCT02204163) on July 30, 2014. URL: https://clinicaltrials.gov/ct2/show/NCT02204163?term=NCT02204163&rank=1.

A case of de novo 18p deletion syndrome with panhypopituitarism.

Deletion on the short arm of chromosome 18 is a rare disorder characterized by intellectual disability, growth retardation, and craniofacial malformations (such as prominent ears, microcephaly, ptosis, and a round face). The phenotypic spectrum is wide, encompassing a range of abnormalities from minor congenital malformations to holoprosencephaly. We present a case of a 2-year-old girl with ptosis, a round face, broad neck with low posterior hairline, short stature, and panhypopituitarism. She underwent ventilation tube insertion for recurrent otitis media with effusion. Brain magnetic resonance imaging showed an ectopic posterior pituitary gland and a shallow, small sella turcica with poor visualization of the pituitary stalk. Cytogenetic and chromosomal microarray analysis revealed a de novo deletion on the short arm of chromosome 18 (arr 18p11.32p11.21[136,227-15,099,116]x1). She has been treated with recombinant human growth hormone (GH) therapy since the age of 6 months after diagnosis of GH deficiency. Her growth rate has improved without any side effects from the GH treatment. This case expands the phenotypic spectrum of 18p deletion syndrome and emphasizes the positive impact of GH therapy on linear growth in this syndrome characterized by growth deficiency. Further studies are required to define the genotype-phenotype correlation according to size and loci of the deletion in 18p deletion syndrome and to predict prognosis.

Identification of a novel mutation in EXT2 in a fourth-generation Korean family with multiple osteochondromas and overview of mutation spectrum.

Multiple osteochondromas (MOs) or hereditary multiple exostoses is a rare autosomal-dominant disease characterized by growths of MOs, which are benign cartilage-capped bone tumors that grow away from the growth plates. Almost 90% of MOs have a molecular explanation and 10% are unexplained. MOs are genetically heterogeneous with two causal genes on 8q24.11 (EXT1) and 11p12 (EXT2), with a higher frequency in EXT1. MO is a very rare genetic disorder, and the genotype-phenotype of MO with EXT2 mutation has not been well investigated in Korea. We present the clinical radiographic and molecular analysis of a four-generation Korean family with 11 MO-affected members (seven males and four females). The affected members from the third generation available for molecular analysis and their detailed medical histories showed moderate-to-severe phenotypes (clinical classes II-III), including bony deformities and limb misalignment with pain requiring surgical correction. The x-rays showed MOs in multiple sites. A novel EXT2 frameshift mutation (c.590delC, p.P197Qfs*73) was revealed by targeted exome sequencing in the affected members of this family. In this article, we not only expand the phenotypic-genotypic spectrum of MOs but also highlight the phenotypic heterogeneity in a family with the same mutation. In addition, we compiled the mutation spectrum of EXT2 from a literature review and identified that exon 2 of EXT2 is a mutation hot spot. Early medical attention with diagnosis of MO through careful examination of the clinical manifestations and genetic analysis can provide the opportunity to establish coordinated multispecialty management of the patient.

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.

First Korean Case of Renpenning Syndrome with Novel Mutation in PQBP1 Diagnosed by Targeted Exome Sequencing, and Literature Review.

Renpenning syndrome is a rare X-linked disorder characterized by mental retardation, leanness, microcephaly, facial dysmorphism, short stature, and small testes. This disease is caused by PQBP1 mutations. Herein, we present a literature review and describe the clinical and molecular findings in a Korean boy with Renpenning syndrome. A 23-month-old boy presented with mental retardation, narrow face, bulbous nose, and cardiac anomaly. Interestingly, targeted exome sequencing identified a novel mutation c.559delT (p.Tyr187llefs*8) in the PQBP1 gene, and he was diagnosed as having Renpenning syndrome. In line with previously reported studies, our case suggests that men with mental retardation, short stature, and microcephaly should include Renpenning syndrome as a differential diagnosis.