FGFR3 Mutation Analysis, p.Gly380Arg, Amniotic Fluid, Next-Generation Sequencing

What Is Being Tested

The test examines the FGFR3 gene, which provides instructions for a protein involved in bone growth and development. It specifically looks for a single known change called p.Gly380Arg (also written G380R), a substitution at position 380 of the protein. This particular change is one of the most common mutations linked to a group of conditions that affect skeletal growth.

Why Your Provider May Order It

This test is typically offered when imaging or other prenatal findings suggest the fetus may have abnormally short limbs or other signs of a skeletal growth condition. Detecting this specific mutation can help confirm a diagnosis and inform counseling about the likely outlook and management. It is not a general screen for all genetic conditions.

How the Sample Is Collected

The sample is amniotic fluid, usually obtained through amniocentesis, a procedure in which a small amount of fluid surrounding the fetus is withdrawn with a needle. The fluid contains fetal cells whose DNA is analyzed. This procedure carries some risks, so your provider will discuss benefits and limitations before testing.

What the Results Mean

A positive result means the specific p.Gly380Arg change was detected, which supports a diagnosis of an FGFR3-related skeletal condition. A negative result means this particular change was not found, but it does not rule out other genetic causes, because many different genes and mutations can produce similar findings. Results should always be interpreted together with imaging and clinical information.