Cardiolipin and monolysocardiolipin analysis in fibroblasts, lymphocytes, and tissues using high-performance liquid chromatography-mass spectrometry as a diagnostic test for Barth syndrome.
Barth syndrome (BTHS) is an X-linked recessive disorder caused by mutations in the tafazzin (or TAZ) gene and is clinically characterized by (cardio)myopathy, neutropenia, and growth abnormalities. Biochemical abnormalities include decreased levels of the mitochondrial phospholipid cardiolipin, increased levels of monolysocardiolipin, and a lower degree of unsaturation of the (monolyso)cardiolipin acyl chains. Diagnostic testing for BTHS is routinely performed by TAZ gene sequencing, and recently a BTHS screening method in bloodspots has been developed, but both methods have important limitations. Because a validated confirmatory method is not yet available, we set up and validated a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for BTHS in cultured fibroblasts, lymphocytes, and skeletal muscle based on cardiolipin, monolysocardiolipin, and the monolysocardiolipin/cardiolipin ratio. In addition, we performed retrospective analysis of 121 muscle samples of patients with myopathy of which mitochondrial origin was presumed, and we identified one patient with cardiolipin abnormalities similar to BTHS patients. Molecular analysis revealed a bona fide mutation in the TAZ gene. We conclude that (monolyso)cardiolipin analysis by HPLC-MS not only is a powerful tool to diagnose patients with clinical signs and symptoms of BTHS but also should be used in patients suffering from mitochondrial myopathies with unknown etiology.
Houtkooper
Riekelt H
RH
Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, 1100 DE Amsterdam, The Netherlands.
Rodenburg
Richard J
RJ
Thiels
Charlotte
C
van Lenthe
Henk
H
Stet
Femke
F
Poll-The
Bwee Tien
BT
Stone
Janet E
JE
Steward
Colin G
CG
Wanders
Ronald J
RJ
Smeitink
Jan
J
Kulik
Willem
W
Vaz
Frédéric M
FM
D000217:Acyltransferases; D002308:Cardiolipins / Q000032:analysis*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005347:Fibroblasts / Q000737:chemistry*; D040181:Genetic Diseases, X-Linked / Q000175:diagnosis*; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry*; D008246:Lysophospholipids / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D009132:Muscles / Q000737:chemistry; D009135:Muscular Diseases / Q000378:metabolism; D012189:Retrospective Studies; D013577:Syndrome; D014157:Transcription Factors / Q000235:genetics
D002308:Cardiolipins; D008246:Lysophospholipids; D014157:Transcription Factors; C067188:monolysocardiolipin; D000217:Acyltransferases; C108675:TAFAZZIN protein, human