Rett syndrome (RS) is a severe neurodevelopmental disorder characterised by normal neurological development followed by progressive developmental regression. The X-linked dominant inheritance of RS has been mapped to the gene that encodes the methyl-CpG-binding protein-2 (MECP2) at Xq28. In the present study, denaturing high-performance liquid chromatography (DHPLC) was used to detect mutations in the MECP2 gene in 20 Malaysian RS patients.
Although an association between protein-truncating variants and breast cancer risk has been established for 11 genes, only alterations in BRCA1, BRCA2, TP53 and PALB2 have been reported in Asian populations. Given that the age of onset of breast cancer is lower in Asians, it is estimated that inherited predisposition to breast cancer may be more significant. To determine the potential utility of panel testing, we investigated the prevalence of germline alterations in 11 established and 4 likely breast cancer genes in a cross-sectional hospital-based cohort of 108 moderate to high-risk breast cancer patients using targeted next generation sequencing. Twenty patients (19%) were identified to carry deleterious mutations, of whom 13 (12%) were in the BRCA1 or BRCA2, 6 (6%) were in five other known breast cancer predisposition genes and 1 patient had a mutation in both BRCA2 and BARD1. Our study shows that BRCA1 and BRCA2 account for the majority of genetic predisposition to breast cancer in our cohort of Asian women. Although mutations in other known breast cancer genes are found, the functional significance and breast cancer risk have not yet been determined, thus limiting the clinical utility of panel testing in Asian populations.
The Academy of Medicine of Malaysia College of Paediatrics acknowledges the role of children in research and this position statement explores the ethical considerations in obtaining assent from minors in the Malaysian context. It highlights the importance in respecting children's agency and navigating cultural complexities. The College proposes flexibility in the minimum age for assent of at least nine years old, while emphasising the need for a tailored assent procedure. Addressing language and cultural diversities and expanding local empirical research on a formal assent process are some building blocks in developing a standardised nationwide process in obtaining assent from children.
Distal renal tubular acidosis (dRTA) caused by mutations of the SLC4A1 gene encoding the erythroid and kidney isoforms of anion exchanger 1 (AE1 or band 3) has a high prevalence in some tropical countries, particularly Thailand, Malaysia, the Philippines and Papua New Guinea (PNG). Here the disease is almost invariably recessive and can result from either homozygous or compound heterozygous SLC4A1 mutations.
The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia.
Familial multiple intestinal atresias is an autosomal recessive disease with or without combined immunodeficiency. In the last year, several reports have described mutations in the gene TTC7A as causal to the disease in different populations. However, exact correlation between different genotypes and various phenotypes are not clear. In this study, we report identification of novel compound heterozygous mutations in TTC7A gene in a Malay girl with familial multiple intestinal atresias and severe combined immunodeficiency (MIA-SCID) by whole exome sequencing. We found two mutations in TTC7A: one that destroyed a putative splicing acceptor at the junction of intron 17/exon 18 and one that introduced a stop codon that would truncate the last two amino acids of the encoded protein. Reviewing the recent reports on TTC7A mutations reveals correlation between the position and nature of the mutations with patient survival and clinical manifestations. Examination of public databases also suggests carrier status for healthy individuals, making a case for population screening on this gene, especially in populations with suspected frequent founder mutations.