Galactosemia (GALT) Sequencing and Deletion/Duplication

Also known as: GALT NGS

Clinical Use

Use

This test is used to detect pathogenic variants in the GALT gene, which is crucial for confirming carrier status or diagnosing galactosemia in individuals with decreased GALT enzyme activity. Galactosemia is a disorder of galactose metabolism due to GALT deficiency, leading to potential life-threatening conditions such as classic galactosemia and clinical variant galactosemia. These can cause symptoms like diarrhea, hepatocellular damage, and sepsis. A lactose-restricted diet initiated early can prevent neonatal complications, though long-term issues may still arise in certain cases. Benign variant galactosemia, like the Duarte variant, does not usually require dietary restrictions. This test aids in deciding appropriate management and genetic consultation recommendations.

Special Instructions

Not provided.

Limitations

A negative result does not exclude the diagnosis of galactosemia. The test detects variants within coding regions and intron-exon boundaries of the GALT gene. It might not detect some deletions, duplications, or insertions by massively parallel sequencing. Regulatory and deep intronic variants are not identified, and diagnostic errors can occur due to rare sequence variations. Some variants may not be detected due to technical limitations like pseudogenes or repetitive regions. This test is not designed to detect low-level mosaic, somatic variants, or some complex genomic events. Results could be affected if the patient has had an allogeneic stem cell transplant.

Test Details