Serine

This test measures the amino acid serine in a blood or urine sample. Serine is one of the building blocks of proteins and plays key roles in brain function, cell membranes, and the production of other molecules such as glycine and certain lipids. Because it sits at a crossroads of many metabolic pathways, serine levels can reflect how your body is making and using amino acids.

Your clinician may request serine as part of a quantitative amino acid analysis. The sample is usually a plasma specimen collected under controlled conditions, or a urine sample that helps assess how amino acids are handled by the kidneys. Testing can help distinguish nutritional, metabolic, or renal causes of symptoms.

Abnormal serine levels can point to inherited metabolic conditions that affect serine biosynthesis or utilization, as well as issues related to nutrition, liver function, or kidney handling of amino acids. Clinicians consider this test when there are concerns about developmental delay, seizures, neuropathy, unexplained metabolic acidosis, or when monitoring treatment in known amino acid disorders.

Serine is closely linked with folate and vitamin B-6 dependent pathways, so levels may also provide clues about vitamin status or the effects of certain medications. Results are most useful when interpreted alongside a full amino acid profile and clinical findings.

Your result is interpreted in the context of your age, the sample type, and the pattern of other amino acids. A lower than expected value may suggest reduced production of serine, nutritional deficiency, or liver dysfunction. A higher than expected value can be seen with increased protein intake, catabolic stress, or kidney impairment that alters amino acid excretion.

If your result is outside the expected interval, your clinician may repeat testing under fasting conditions, review medications and supplements, and consider additional studies such as a comprehensive amino acid profile, vitamin assessments, or genetic testing. Follow-up depends on your symptoms and medical history, and many causes are treatable once identified.