SERUM VERY LONG CHAIN FATTY ACIDS LEVEL MEASUREMENT AS METHOD OF FAMILY SCREENING FOR HEMI AND HETEROZYGOTES OF X-LINKED ADRENOLEUKODYSTROPHY/ADRENOMYELONEUROPATHY

Objective X-linked adrenoleukodystrophy/adrenomyeloneuropathy (X-ALD/AMN) is caused by a defect of the ABCD1 gene, which codes membrane ALDP transporter protein. The gene was localised in the 28q X chromosome. The disturbance of the transport of the very long chain fatty acids (VLCFA) C24:0 and C26:0 increases their levels in tissues and body fluids. Symptoms and signs are a consequence of myelin, adrenal cortex and testes impairment. Hemizygotes present progressing demyelinisation of central and peripheral nervous system and adrenal insufficiency. Patients with AMN also present hypogonadism, impairment of Leydig’s cells and decrease of testosterone level. Methods and Results Affected patients with X-ALD/AMN are identified by the presence of increased VLCFA levels determinates as derivatives esters using gas chromatographic methods. Among 10 married adult men with X-ALD/AMN seven had 11 children (7 girls and 4 sons). In seven patients with AMN (mean ± SD 35.1 ± 3.9 years) the VLCFA levels (mean ± SD) were C24:0/C22:0 1.689 ± 0.08 and C26:0/C22:0 0.061 ± 0.02. In patients’ daughters (mean ± SD 7.7 ± 2.4 years) as in obligatory heterozygotes, the presence of increased VLCFA was proved (C24:0/C22:0 1.090 ± 0.11 and C26:0/C22:0 0.022 ± 0.08). Conclusion In X-ALD/AMN patients with late onset the possibility of procreation and obligatory carriership of their daughters should be taken into consideration. In our investigated group, decreased fertility among X-ALD/AMN patients was not observed. Genetic counselling should involve X-ALD/AMN patients and their daughters—obligate carriers.