Primary hypomagnesemia with secondary hypocalcemia is a rare autosomal recessive disorder characterized by profound hypomagnesemia associated with hypocalcemia. Pathophysiology is related to impaired intestinal absorption of magnesium accompanied by renal magnesium wasting as a result of a reabsorption defect in the distal convoluted tubule. Recently, mutations in the TRPM6 gene coding for TRPM6, a member of the transient receptor potential (TRP) family of cation channels, were identified as the underlying genetic defect. Here, the results of a TRPM6 mutational analysis of 21 families with 28 affected individuals are presented. In this large patient cohort, a retrospective clinical evaluation based on a standardized questionnaire was also performed. Genotype analysis revealed TRPM6 mutations in 37 of 42 expected mutant alleles. Sixteen new TRPM6 mutations were identified, including stop mutations, frame-shift mutations, splice-site mutations, and deletions of exons. Electrophysiologic analysis of mutated ion channels after heterologous expression in Xenopus oocytes proved complete loss of function of TRPM6. Clinical evaluation revealed a homogeneous clinical picture at manifestation with onset in early infancy with generalized cerebral convulsions. Initial laboratory evaluation yielded extremely low serum magnesium levels, low serum calcium levels, and inadequately low parathyroid hormone levels. Treatment usually consisted of acute intravenous magnesium supplementation leading to relief of clinical symptoms and normocalcemia, followed by lifelong oral magnesium supplementation. Serum magnesium levels remained in the subnormal range despite adequate therapy. This is best explained by a disturbed magnesium conservation in the distal convoluted tubule, which emerged in all patients upon magnesium supplementation. Delay of diagnosis resulted in permanent neurologic damage in three patients.

This study demonstrates that adolescents with type 1 DM and higher self-efficacy, especially males, have a higher probability of reaching target diabetes control.

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Total iodide organification defect (TIOD), where the iodide in the thyroid gland cannot be oxidized and/or bound to the protein, is caused by a defect in the thyroid peroxidase (TPO) gene. Single strand conformation polymorphism analysis was used to screen for mutations in the TPO gene from five unrelated TIOD patients in Taiwan, and five novel mutations were detected. Three of these were frameshift mutations: a single T insertion between nucleotide position 2268 and 2269 (c.2268-2269 insT) in exon 13 and two single C deletions at nucleotide positions 843 (c.843 delC) and 2413 (c.2413 delC) in exon 8 and 14 respectively. The other two were single nucleotide substitutions (c.G1477>A and c.G2386>T) located in exons 9 and 13 respectively. While the former would result in amino acid substitution (Gly493Ser) in the highly conserved region of the TPO polypeptide, the latter would result in either amino acid substitution (Asp796Tyr) or alternative splicing. Of those identified TPO mutations, c.2268-2269 insT was most prevalent and was detected as heterozygous in all but one TIOD patients. All five TIOD patients investigated in this study were compound heterozygous. The method presented in this study could be used for carrier assessment and mutation analysis of newly identified TIOD patients.

To improve treatment results for children with de novo acute myeloid leukemia (AML), we introduced a novel protocol, Taiwan Pediatric Oncology Group-AML-97A, for AML other than acute promyelocytic leukemia (APL), for which modified conventional protocols were used. From January 1, 1997, to December 31, 2002, 141 children younger than 17 years old with de novo AML were enrolled. In total, 117 patients with non-APL AML were treated with induction therapy of idarubicin and cytarabine (Ara-C), postremission therapy with high-dose Ara-C -containing regimens for four monthly courses, and moderatedose therapy with idarubicin and Ara-C for four monthly courses. The first 19 patients with APL were treated with alltrans retinoic acid, idarubicin and Ara-C, with the remaining five patients receiving all-trans retinoic acid and idarubicin, followed by maintenance therapy for 2 years. Stem cell transplantation was performed in 29 patients in first remission with a similar outcome as chemotherapy alone. The remission rate in the AML-97A study was 90%, the 5-year survival 5175.3% (s.e.) and the 5-year event-free survival 5074.8%; for APL, these were 100%, 8677.0, and 7579.8%. For the whole group, the 5-year survival was 5774.7% and the 5-year event-free survival 5474.4%. The AML-97A regimen was well tolerated.

Seventeen alpha-hydroxylase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia in which defects in the biosynthesis of cortisol and sex steroid result in mineralocorticoid excess, hypokalemic hypertension and sexual abnormalities such as pseudohermaphroditism in males, and sexual infantilism in females. The disease is inherited in an autosomal recessive pattern, and is caused by mutations in the gene encoding cytochrome P450c17 (CYP17), which is the single polypeptide that mediates both 17alpha-hydroxylase and 17,20-lyase activities. We report the case of a 15-year-old patient with 17OHD who had a female phenotype but male karyotype (46,XY). The diagnosis was made based on classical clinical features, biochemical data and molecular genetic study. Two mutations were identified by polymerase chain reaction amplification and sequencing, including a S106P point mutation in exon 2 and a 9-bp (GACTCTTTC) deletion from nucleotide position 1519 in exon 8 of CYP17. The first of these mutations was found in the father and the second in the mother, and both have been previously reported in Asia. The patient's hypertension and hypokalemia resolved after glucocorticoid replacement and treatment with potassium-sparing diuretics. Sex hormone replacement was prescribed for induction of sexual development and reduction of the final height. Prophylactic gonadectomy was scheduled. In summary, 17OHD should be suspected in patients with hypokalemic hypertension and lack of secondary sexual development so that appropriate therapy can be implemented.

Noonan syndrome is a highly variable disorder that has significant phenotypic overlap with Costello syndrome and cardio-facio-cutaneous syndrome. KRAS mutation was the second reported gene for Noonan syndrome. This study screened for mutation of the KRAS gene in 57 unrelated ethnic Chinese children suffering from Noonan syndrome without PTPN11 gene mutation in Taiwan. This work only identified two patients with different missense mutations (c.40G>A, p.Val14Ile; c.108A>G, p.Ile36Met) in the exon 1 of KRAS gene. This study also analyzed the characteristics of 34 reported cases involving KRAS mutations in the literature. All these patients presented with variable phenotypes, including Noonan syndrome (n = 19), cardio-facio-cutaneous syndrome (n = 7), Costello syndrome (n = 6), and Noonan/cardio-facio-cutaneous syndrome (n = 1). The phenotype of KRAS mutations was generally severe, including short stature, mental retardation, heart defects, etc. In conclusion, this investigation demonstrates that KRAS mutations are the cause in a minority of cases of Chinese patients with Noonan syndrome in Taiwan.

It is important for clinicians to work out a comprehensive plan to help the motor development of patients with Williams syndrome in addition to treating their medical problems, and upper limb dexterity may be the goal for training.