[Clinical characteristics of X-linked adrenoleukodystrophy]

X-linked adrenoleukodystrophy (ALD) is a genetically determined disorder that involves the nervous system white matter, axons, adrenal cortex and testes. The typical clinical manifestations are progressive psychomotor regression, vision and/or auditory impairment and adrenal insufficiency. The clinical manifestation, biochemical change and genetic counseling work of X-linked ALD were analyzed.

The clinical features of 29 cases with ALD were summarized and analyzed, including symptoms and signs, measurement of blood very long chain fatty acids (VLCFA), adrenal function, cranial magnetic resonance imaging (MRI) and pedigree investigation.

Among these 29 cases, the clinical phenotype could be classified into childhood cerebral (22 cases), adolescent cerebral (4 cases), adrenomyeloneuropathic (1 case), Addison's disease (1 case) and asymptomatic or presymptomatic (1 case) types. Nine of them had positive family history. Pedigree investigation was consistent with typical sex-linked recessive inheritance. There were 45 ALD patients in these 29 pedigrees. The neurological manifestations varied among members of the same family. Nine cases died during follow up. The causes of death were central respiratory failure or other complications of ALD and so on. Laboratory tests demonstrated abnormally high plasma levels of VLCFA in ALD patients; MRI demonstrated symmetric butterfly-like low T(1) and high T(2) signals in the parieto-occipital white matter. The impairment in the splenium of corpus callosum made the bilateral lesion region converge into one. It could progress anteriorly and injure the bilateral posterior limb of internal capsule and the temporal lobe, and could injure the brainstem inferiorly. Following intravenous injection of contrast material, thin stripe of lacelike enhancement could be observed.

The atypical initial symptom of ALD was seizures. The MRI showed abnormal signal in the cerebellar white matter. This disease can influence the normal development of children, this was more pronounced in the childhood cerebral ALD type. It tended to progress rapidly with dementia, vegetative state or death. Since antenatal diagnostic method is available now, emphasis should be made on the antenatal examination in order to make an early diagnosis and abort pregnancy if necessary.