Due to the growing demand of genetic testing for DMD and SMA in our region, we have been developing our human resources capabilities and infrastructure for DMD and SMA genetic testing. Our recent collaboration with expertise from overseas including several seminars, workshops and joint research also helped us to improve our capabilities regarding the genetic testing.
Duchenne Muscular Dystrophy (DMD)
The DMD gene is the largest known human gene, consisting of 79 exons spanning 2.2 Mb. The most identified mutations in DMD are deletions, responsible for approximately 60-65% of DMD and 85% of BMD mutations, while duplications were observed in 5-15% of DMD patients. The remaining maybe caused by small mutations including microdeletions, point mutations or splicing mutations. Therefore, in our institution we have developed our own pipeline on MLPA (Multiplex Ligation Probe Amplification) and multiplex polymerase chain reaction (PCR) analysis of DMD which can cover the copy number variant (deletion or duplication) of the DMD gene.
Spinal Muscular Atrophy (SMA)
The most common form of SMA is associated with the loss of survival motor neuron (SMN) protein, which is encoded by 2 or more genes on chromosome 5. The majority of this protein is expressed by the survival motor neuron 1 (SMN1) gene, but a small portion is also contributed by the survival motor neuron 2 (SMN2) gene. SMA is most commonly caused by a homozygous deletion of exon 7 in SMN1. However, some patients with this disorder may be compound heterozygotes, with a deletion of 1 copy of SMN1 and a nucleotide variant in the other allele. The severity of a patient’s disease course is associated with the number of copies of SMN2 that are present, and 3 or more SMN2 copies are associated with a milder SMA phenotype. In our faculty, we have developed several techniques of SMN 1 deletion test including polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP), MLPA and also qPCR methods.
Reference:
Dwianingsih EK, Iskandar K, Li CP, Malueka RG, Gunadi., Pratiwi L, Hapsara S, Matsuo M, Lai PS. DMD gene analysis of Duchenne and Becker muscular dystrophy patients in Indonesia. J Neuro Sci. 2019.405:273 (abstract)
Iskandar K, Dwianingsih EK, Pratiwi L, Kalim AS, Mardhiah H, Putranti AH, Nurputra DK, Triono A, Herini ES, Malueka RG, Gunadi, Lai PS, Sunartini. The analysis of DMD gene deletions by multiplex PCR in Indonesian DMD/BMD patients: the era of personalized medicine. BMC Res Notes. 2019;12:704.
Contact us:
Genetics Working Group (Pokja Genetik)
Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada
Jl. Kesehatan No. 1 Yogyakarta 55281 Indonesia
Ph./Fax: 62274631036
Email: pokjagenetikugm@gmail.com
Web: https://pokjagenetik.fk.ugm.ac.id/genetic-testing-registry/