Answer:

Spinal muscular atrophy (SMA) is a group of hereditary diseases affecting motor nerve cells, with a carrier rate of approximately 1/50. It is an autosomal recessive disorder, meaning that an affected child inherits two mutated genes, one from each parent. In rare cases, a new mutation can occur spontaneously during embryonic development.

The disease gradually destroys nerve cells in the brainstem and spinal cord that control essential skeletal muscle activities such as speaking, walking, breathing, and swallowing. Patients with SMA may experience weakness, muscle atrophy, difficulty with movement or breathing, skeletal deformities, and potentially death.

Currently, scientists have developed treatments for SMA, but the cost can be as high as 50 billion VND. Prenatal ultrasound detection is limited, as it primarily identifies severe cases. Most cases manifest after birth, around 4-5 months of age.

According to The American College of Obstetricians and Gynecologists (ACOG), couples planning to marry or conceive should undergo SMA genetic screening to minimize the risk of having a child with the disease. If you and your husband have not yet had genetic testing, you should be tested during this pregnancy to determine if you carry the recessive gene and to assess whether your previous child's condition was due to inherited genes or a spontaneous mutation. Your doctor will then advise on diagnostic options for this pregnancy.

Blood test for genetic screening before pregnancy. Illustrative photo: Tam Anh General Clinic, District 7

If both parents are found to carry the recessive gene, the doctor may recommend chorionic villus sampling at 12 weeks of pregnancy or amniocentesis at 16 weeks to diagnose whether the fetus has SMA. If the fetus is diagnosed with SMA and you wish to continue the pregnancy, your doctor will create a suitable prenatal care plan. Medical intervention may be possible immediately after birth to slow the disease's progression and improve the child's quality of life. If you choose to terminate this pregnancy, in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD) can be considered for future pregnancies. This allows for the screening and selection of healthy embryos for transfer to the uterus.

Nguyen Phuong Thao, MSc, MD, Specialist Level I

Fetal Medicine Specialist

Tam Anh General Clinic, District 7