Clinical Guidance

Serine deficiency disorders include a spectrum of disease ranging from lethal prenatal-onset Neu-Laxova syndrome to adult-onset serine deficiency characterized by progressive polyneuropathy. Several clinical phenotypes can be identified: prenatal onset, infantile onset, juvenile onset, and adult onset. To date, more than 50 individuals have been identified with biallelic pathogenic variants in PHGDH, PSAT1, or PSPH [, , , , , , , , ]. The majority of individuals reported have the infantile-onset phenotype. The following description of the phenotypic features associated with this condition is based on these reports.

Diagnostic Criteria

No consensus clinical diagnostic criteria for serine deficiency disorders have been published.

Suggestive Findings

A serine deficiency disorder should be suspected in individuals with the following clinical, imaging, and laboratory findings and family history. Clinical and brain MRI findings can vary between phenotypes:

• Prenatal onset (Neu-Laxova syndrome)

Source: GeneReviews — "Serine Deficiency Disorders"

Management Guidelines

No clinical practice guidelines for serine deficiency disorders have been published. Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with a serine deficiency disorder, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 3. Serine Deficiency Disorders: Recommended Evaluations Following Initial Diagnosis

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 5. Recommended Surveillance for Individuals with Serine Deficiency Disorders