Diagnosing spinal muscular atrophy

An analysis of the diagnosis of spinal muscular atrophy can be offered to patients who have had amniocentesis or chorionic biopsy.

Spinal muscular atrophy or SMA is one of the most common fatal childhood genetic diseases. The incidence rate of SMA is 1/10,000. The incidence rate does not depend on the child's sex.

SMA is an autosomal recessive genetic disease. For a child to be affected, he/she has to have two defective SMA-causing genes. Healthy parents carry one SMA-causing gene which they both pass to their child who will therefore become ill. This disease is characterised by degeneration of spinal nerve cells which causes weakness and atrophy of skeletal muscles.

The most serious type is SMA type 1 which begins in utero or during the first months of life. The majority of children with this diagnosis die before the age of 2.

With SMA type 2, the child will develop close to normal until 6 months of age, after that development will slow down and motor skills will start to decline. Parents' first complaint is that the child won't start walking. Some children die in childhood due to respiratory disorders, but the majority will reach adulthood.

SMA type 3 is the mildest and of slowliest progression of all three SMA types. It begins between the ages of 5-15 and presents as a general muscle weakness and atrophy.

Although 3 different drugs have been registered in Europe and the USA for the treatment of SMA in recent years, clinical studies regarding their effectiveness and long-term consequences are few. From January 2022, one of the medicines will also be available in Estonia. The earlier the treatment is started, the better the long-term results of the studies.

Spinal muscular atrophy analysis response comes 14 days after the invasive procedure.

The cost of the study includes contamination of the chorion and/or amnion cells with maternal material. The cost of a chorionic biopsy or amniocentesis is added to the price.