Purpose: The aim of this study is to analyse the usage of Continuous Glucose Monitoring System (CGMS) among paediatric population with type 1 diabetes in Hong Kong. Methods: Data was retrieved from the Hong Kong Childhood Diabetes Registry. Paediatric patients with type 1 diabetes with active follow-up in Hospital Authority in 2018 were included. Results: Three hundred and sixty patients were included in the analysis. Only 38 patients (10.6%) were regular CGMS users. The mean HbA lc of regular users was significantly lower than that of the non-regular CGMS users (7.4 +/- 1.2% vs. 8.5 +/- 1.9%; P=0.0003). The difference was still significant after adjusting for age, use of insulin pump and parents' occupations (P=0.038). The regular usage of CGMS was associated with younger age, use of insulin pump and higher socioeconomic position. Conclusions: The overall usage of CGMS among paediatric patients with type I diabetes in Hong Kong was relatively low.

Background: Anaphylaxis and severe systemic allergic reaction are potentially life-threatening conditions. There is a paucity of data on the management of such condition amongst Hong Kong children. Objective: This review was designed to assist health professionals to evaluate the current process of care for children admitted with anaphylaxis or severe systemic allergic reaction, to identify service gaps so that patients are appropriately investigated, treated and taught how to recognise and manage severe allergic reactions. Methods: The anaphylaxis and severe allergic reaction/angioedema for children under age of 18 were identified using ICD-9 codes 995.0, 995.1, 995.6. We performed a retrospective chart review of one hundred children. We assessed the clinical practice among all Paediatric Departments within the Hospital Authority (HA) from January 2006 to December 2007. Results: The standardised admission rates of anaphylaxis aged below 18 years was 0.5/100,000 (Cl 0.6-0.7), which was probably 5-7 fold less compared with Western countries. This territory wide survey confirmed that food allergy was the leading cause in systemic allergic reactions amongst children admitted to HA service. Drug was the second commonest cause, accounting for 24% of the cases. The causes could not be determined in one out of six cases (17%). The attempt to identify the exact aetiologies was hampered by the lack of allergy assessment in most of the units. Adrenaline auto-injector was infrequently prescribed and used in our practice. Conclusion: This study provided background information for possible implementation of improvement measures that might be needed in the management of this possible life-threatening reaction.

Objectives: To update the incidence of type 1 and type 2 diabetes in children aged <19 years from 1997 to 2007 in Hong Kong. Methods: Retrospective population-based incidence study. Primary ascertainment: reviewing medical records of diabetes patients in all public hospitals. Secondary ascertainment: impractical upon implementation of personal data privacy ordinance in Hong Kong. Results: Type 1 diabetes: Standardised age-adjusted incidence was 2.4/100,000/yr for children aged <15 years. Significant increase in incidence rate was shown (Slope=0.11/100,000/yr; R 2 =0.40; p=0.036). There was a significant increase in incidence in 0-4-year age-group. Type 2 diabetes: Standardised age-adjusted incidence was 2.1/100,000/yr for 10-18-year age-group. Significant increase in incidence rate was shown (Slope=0.314/100,000/yr; R 2 = 0.711; p=0.001), with a sharp rise after 2004. Conclusions: Standardised age-adjusted incidence of childhood type 1 diabetes remained low while that for type 2 diabetes was newly determined. A definite increase in incidence for both types was shown (1997-2007), with a trend towards younger age of onset.

Osteoporosis pseudoglioma syndrome (OPPG) is an autosomal recessive disorder due to mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. Here, we report two novel missense mutations found in a southern Chinese family of a non-consanguineous marriage. Three out of four children had blindness, low bone mineral density (BMD) and multiple fractures in their childhood. Genotyping by DNA sequencing demonstrated 2 new mutations in exon 7 of the LRP5 gene. Tryptophans at amino acid residue positions 478 and 504 were replaced by arginine (W478R) and cysteine (W504C), respectively. While the parents that possessed either heterozygous W478R or W504C were apparently normal, all affected subjects were compound heterozygotes for the W478R and W504C mutations in the LRP5 gene. W478R is located immediately C-terminal to the third YWTD repeat of the second YWTD/EGF domain in LRP5, while W504C is located between the third and the fourth YWTD repeats of the second YWTD/EGF domain in LRP5. Using LRP5-related proteins, such as the low-density lipoprotein receptor (LDLR) and nidogen as reference models, a homology model of LRP5 suggested that the observed mutations may affect the molecular interactions of LRP5 and so lead to the observed OPPG phenotypes.

Objectives: To describe the clinical characteristics of 3 patient with 6-pyruvoyltetrahydropterin synthase (PTPS) deficiency.

Cystinuria is a recessively inherited aminoaciduria that leads to recurrent urolithiasis. It is caused by the defective transport of cystine and dibasic amino acids in the proximal renal tubules and intestinal epithelium. Two genes responsible for this, SLC3A1 and SLC7A9, are known. Patients with two SLC3A1 mutations are classified as type A cystinuria, whereas patients with two SLC7A9 mutations are classified as type B cystinuria. Few clinical and molecular data have been reported for Asian cystinuria patients. In this study, we determined the molecular basis of cystinuria in eight unrelated Chinese subjects. Coding exons and flanking introns of the SLC3A1 and SLC7A9 genes were directly sequenced after amplification by polymerase chain reaction. Five different SLC3A1 mutations were found. Two missense mutations, D210G and S547L, were novel. The other three SLC3A1 mutations (IVS6+2T>C, R181Q and R365W) have been described previously. In addition, four novel SLC7A9 mutations, C137R, c.730delG, IVS10+2_3delTG and IVS12+3insT, together with two previously reported mutations (A70V and G195R) were found. All patients except one carried compound heterozygous mutations. IVS12+3insT was detected in patients from two families. This is the first molecular genetic study on Chinese cystinuria patients. Three patients with type A cystinuria, two with type B cystinuria, and three carriers of type B cystinuria were identified. Our results suggest that the molecular basis of cystinuria is heterogeneous in our local population.

Congenital infantile myofibromatosis is a rare disorder with multiple fibromatous tumours in skin, bone, muscle, viscera and subcutaneous tissue presenting in early infancy. Multiple lytic bone lesions and vertebra involvement are also common, mimicking the clinical picture of metastatic tumours. However, it is a disease with variable prognosis depending on the type and extent of involvement. Spontaneous resolution occurs in most of the cases without visceral involvement. We report good outcome in a case of multicentric type of infantile myofibromatosis with no visceral involvement. Invasive investigations and aggressive intervention should be avoided in these cases.

There has been long standing concern about the safety of measles-mumps-rubella vaccine in children with history of egg allergy. We review our experience in vaccinating such children in our hospital over a four- year period. Clinical evidences on the risk of anaphylactic reaction after measles-mumps-rubella vaccination is reviewed. A revised recommendation for the vaccination of children with history of egg allergy is proposed.

Phaeochromocytoma is a rare disease in childhood with a subtle and wide range of clinical presentations. We report two confirmed cases and one potential case of phaeochromocytoma, each belonging to a different disease spectrum or syndromal disorder, namely sporadic phaeochromocytoma, von Hippel-Lindau disease, and multiple endocrine neoplasia type 2a. Knowledge of the molecular basis of the condition helps to make the diagnosis. Affected individuals and their family members should be screened for any associated syndromal disorders that can carry a substantial degree of morbidity and mortality.