Icahn School of Medicine at Mount Sinai
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Genetic Testing Lab

Test Catalog Molecular Genetics Laboratory X Linked Protoporphyria

X Linked Protoporphyria

Test Description:
EPP and XLP are both protoporphyrias with similar symptoms and similar biochemical findings, but each is caused by mutations in a different gene. XLP is sometimes called a “variant form of EPP”. XLP an X-linked disorder, caused by a mutation in exon 11 of the ALAS2 gene, resulting in an increased production of the enzyme, aminolevulinic acid-synthase 2.

Symptoms usually first occur in early childhood, and include sun sensitivity, marked by severe pain and swelling of sun-exposed areas, but typically with no blistering or scarring. Males and females are both affected, although females are typically less severe. Both XLP and EPP result in significant elevations of protoporphyrins in the liver, sometimes resulting in severe liver complications that are difficult to treat and sometimes require liver transplantation.

Specimen Requirements:
Two 10 mL EDTA (lavendar top) tubes and one 10 mL ACD (yellow top) tube. Two to three confluent T-25 flasks of cultured cells and one control flask are required for prenatal samples.

Shipping: Send at room temperature.

Turnaround Time: 14 days

CPT Codes: 83891, 83898, 83904x2, 83912

Consent Form: Porphyria Genetic Testing Consent [PDF]

Requisition Form: Porphyria Testing Requisition [PDF]

Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.