LPC Derivatives of Very Long-Chain Fatty Acids (VLCFA) — Dried Blood Spot Test

A specialised dried blood spot (DBS) test measuring lysophosphatidylcholine (LPC)
derivatives of very long-chain fatty acids (VLCFA) — the most sensitive and specific
biochemical marker for peroxisomal disorders, including X-linked adrenoleukodystrophy (X-ALD), Zellweger spectrum disorder, and related conditions. Available to patients and clinicians across the European Union.

What is the LPC-VLCFA test?

Very long-chain fatty acids (VLCFA) are fatty acids with carbon chains of 22 carbons or more. Under normal conditions, VLCFA are broken down inside cellular organelles called peroxisomes. When peroxisomal function is impaired — due to inherited genetic defects — VLCFA accumulate in tissues and body fluids, causing progressive and often severe neurological and systemic damage.

The measurement of lysophosphatidylcholine (LPC) derivatives of VLCFA from a dried blood spot sample represents the current gold standard for peroxisomal disorder screening. LPC- bound VLCFA offer superior analytical sensitivity and specificity compared to traditional free VLCFA measurement, enabling earlier and more reliable detection — even in female carriers of X-linked conditions.

This test measures three key LPC-VLCFA species:

• LPC 26:0 — lysophosphatidylcholine with C26:0 (hexacosanoic acid)
• LPC 26:1 — lysophosphatidylcholine with C26:1
• LPC 24:0 — lysophosphatidylcholine with C24:0 (lignoceric acid)

The analysis is performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) at our specialist laboratory in Warsaw.

Which rare diseases can this test detect?

X-linked adrenoleukodystrophy (X-ALD): The most common peroxisomal disorder, caused by mutations in the ABCD1 gene. X-ALD affects the nervous system and adrenal glands, with clinical presentations ranging from childhood cerebral form (CCALD) to adrenomyeloneuropathy (AMN) in adults, and adrenal insufficiency (Addison disease).

Zellweger spectrum disorder (ZSD): A group of severe peroxisome biogenesis disorders caused by mutations in PEX genes, ranging from Zellweger syndrome to neonatal adrenoleukodystrophy and infantile Refsum disease.

ACOX1 deficiency: A deficiency of acyl-CoA oxidase 1 — the first enzyme in peroxisomal fatty acid beta-oxidation — leading to VLCFA accumulation and progressive neurological deterioration.

D-bifunctional protein (DBP) deficiency: A severe peroxisomal disorder affecting fatty acid oxidation, presenting in the neonatal period.

Why LPC-VLCFA rather than traditional VLCFA testing?

• Higher sensitivity — detects affected individuals and carriers with greater reliability
• Female carrier detection — traditional VLCFA testing misses a significant proportion of female X-ALD carriers; LPC-VLCFA substantially improves detection rates
• DBS compatibility — enables home-based sample collection and stable postal
  shipping
• Suitable for newborn screening — used in several national newborn screening
  programmes in Europe and the USA

Who is this test for?

• Male children with suspected X-ALD — unexplained neurological deterioration, white matter disease on MRI, or adrenal insufficiency
• Adult males with progressive spastic paraparesis or adrenomyeloneuropathy of
  unknown cause
• Female carriers of X-ALD mutations — for biochemical confirmation
• Newborns or infants with suspected Zellweger spectrum disorder
• Patients with unexplained progressive leukodystrophy or white matter abnormalities
• Family members of patients with confirmed peroxisomal disorders — for cascade
  screening
• Clinicians and neurologists investigating peroxisomal disease
• Researchers studying peroxisomal biology or VLCFA metabolism

Frequently Asked Questions