Rare Genetic Disorders for Future Genetic Investigations

The Genetic Disorders Hub aims to improve the outcome of patients suffering from rare genetic disorders with an initial focus on 2 diseases, namely Duchenne Muscular Dystrophy (DMD) and Pulmonary Arterial Hypertension (PAH).

DMD is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact. DMD is a severe form of dystrophinopathies and the milder form of the disease is known as Becker Muscular Dystrophy (BMD). Duchenne and Becker muscular dystrophies (DMD/BMD) are the most commonly inherited neuromuscular disease. Every year from the 5,000,000 live births in Indonesia, approximately 500-700 cases of DMD will be born. If left untreated, these children will suffer progressive muscular weakness, will be wheelchair-bound by the time they are 10-12 years old, and will suffer premature death within the second decade of their lives.

Current clinical management in Indonesia relies on diagnosis based on clinical features and muscle biopsy. Treatment is limited to supportive treatment and steroids. This aims to demonstrate that using a genomic approach, diagnostic and clinical management will be improved. International guidelines mandate the use of genetic testing as it is precise, cost and time-effective but the ability to conduct these tests in Indonesia remains limited. The Genetic Disorder Hub aims to build the capacity to conduct these tests in-country, using targeted NGS sequencing as a comprehensive diagnostic tool for all mutations.

Pulmonary arterial hypertension (PAH), is also a rare, progressive condition defined by high blood pressure in the pulmonary arteries, for which there are typically no identifiable causes. Symptoms of PAH include dyspnea, particularly following strenuous activity, chest discomfort, and fainting. There are currently no national statistics or profiles on PAH incidences in Indonesia but among the PAH cases being treated at RSUP Dr. Sardjito, approximately more than 80% are associated with Congenital Heart Disease (CHD).

Recent research has demonstrated that genetic alterations play a significant role in the development of PAH. The first gene identified in IPAH and HPAH patients was BMPR2. In subsequent years, it was discovered that this gene contributes to the vascular remodeling process in PAH. In a separate study conducted in China, the BMPR2 mutation was shown to be more prevalent in the CHD-PAH group than in the CHD group without PAH, indicating a genetic predisposition in some individuals. Various genes, including ALK1, ENG, SMAD9, SMAD1, CAV1, TBX4, KCNK3, and EIF2AK4, which are also involved in pulmonary vascular remodeling, have been identified as actors in PAH with the introduction of new sequencing technology.

Using whole genome sequencing, the purpose of this study is to identify the key risk genes for PAH in Indonesia, as well as to examine the association between the major risk genes and the unique patterns of PAH patients in Indonesia. It is believed that this genetic data will serve as the foundation for future genetic investigations and will be beneficial for recognizing the risk of PAH, hence facilitating clinical decision-making in the management and therapy algorithms for PAH patients in general.

Vision

The project is aimed at elucidating the genetic determinants of DMD and CHD-PAH associated with disease severity in young DMD and PAH cases, with the hope of reducing the national health and economic burden of DMD and CHD-PAH.

Disease Target

• Duchenne Muscular Dystrophy
• Pulmonary Arterial Hypertension

Outcome

DMD

• National registry of DMD
• Genetic testing and defining genetic etiology
• Genetic diagnosis guides treatment
• Screening and counseling of family members
• Genomic screening in preventive health

PAH

• National registry of PAH
• National policy for school-age screening of CHD
• Genetic determination of PAH in CHD in young age
• Integrated genetic and familial screening of PAH
• Integrated Genetic and Early Screening of PAH
• Genetic Determination for Personal Intervention in CHD-PAH
• Personalized Genetic Marker for Responsiveness of PAH drug