Congenital adrenal hyperplasia (CAH), an autosomal recessive disorder, is due to deficiency of the enzymes involved in adrenal steroidogenesis. Phenotypic manifestations vary as a result of the degree of glucocorticoid or mineralocorticoid deficiency and androgen excess present. Among Filipinos, the estimated crude incidence of CAH is approximately 1 in 7,000, which is higher than what is reported in most populations. More than 90% of all cases result from a 21-hydroxylase (21-OH) (cytochrome P450c21) enzyme deficiency involving two 21-OH genes, the active gene (CYP21) and a pseudogene (CYP21P). Studies have shown that mutations result from unequal crossover during meiosis which leads to complete deletion of the gene, gene conversion events or to point mutations. To date, there are no published data on the types of mutations present among Filipinos diagnosed with congenital adrenal hyperplasia. The objective of this study is to describe the profile of Filipino patients diagnosed with CAH and to determine the disease-causing alleles in the 21-OH gene of these patients. Using a method of combined differential polymerase chain reaction and amplification created restriction site approach, direct probing for the presence of known mutations in exons 1,3,4,6,7,8 and intron 2 of the CYP21 and CYP21P genes among Filipino patients with CAH was performed. A total of 12 unrelated CAH patients were examined. A majority of these cases had a premature splicing error mutation at nucleotide 656 of intron 2. The determination of the most frequent alleles in our population can facilitate rapid screening for mutations in the 21-OH gene and lead to a definitive diagnosis of CAH.

Human ; Male ; Female ; Steroid 21-hydroxylase ; Adrenal Hyperplasia, Congenital ; Introns ; Glucocorticoids ; Mineralocorticoids ; Alleles ; Pseudogenes ; Rna Splicing ; Nucleotides

Background. Glucose-6-phosphate (G6PD) deficiency is the most prevalent enzyme deficiency to date. The global prevalence of G6PD deficiency is estimated at around 330 million people affected with the disease worldwide. This 4.9 percent prevalence, correlates highly with geographic areas endemic to malaria. It is the most common among the disorders in the Newborn Screening (NBS) panel in the Philippines, with one confirmed case for every 52 newborns (1:52). This paper determines the molecular background of G6PD deficiency among Filipino newborns detected by newborn screening. Methods. A total of 200 cases confirmed to have G6PD deficiency, 180 males and 20 females, were identified through the Philippine Newborn Screening Program from 2001-2003. Genomic DNA was extracted from dried blood spots followed by multiplex polymerase chain reaction using multiple tandem forward primers and a common reverse primer (MPTP) to detect previously reported common mutations and polymorphisms in exons 5, 6, 9, 11 and 12 of the G6PD gene. Results. Of the 200 samples analyzed, mutations and polymorphisms in the G6PD gene were identified in 148 cases (74%). The most common mutation was a G to A transition on nucleotide 871 (Viangchan) of exon 9 in combination with a silent mutation on exon 11, accounting for 32.9% of the cases. This was followed by a C to T transition on nucleotide 1360 (Union) in 21.1 % of the cases. Other mutations were Vanua Lava in 10%, Chatham in 9.4% and Canton in 3.5% of the newborns. The silent polymorphism on nucleotide 1311 was present in 12.9% of cases. There were combinations of these mutations and polymorphisms present in a minority of cases. Conclusion. Results of this study showed the molecular heterogeneity underlying G6PD deficiency among Filipino newborns.
Human ; Male ; Female ; Infant ; Infant Newborn ; GLUCOSEPHOSPHATE DEHYDROGENASE DEFICIENCY ; HEMIC AND LYMPHATIC DISEASES ; HEMATOLOGIC DISEASES ; ANEMIA ; ANEMIA, HEMOLYTIC ; ANEMIA, HEMOLYTIC, CONGENITAL ; NEONATAL SCREENING ; INFANT, NEWBORN, SCREENING ; NEWBORN INFANT SCREENING ; MUTATION