Clinical classification of XXXX subtypes.

@entity1 @entity410 @entity2045 @entity56580 @entity12030 @entity179 @entity194 @entity3519
@entity12030 is the most common class of @entity179 in @entity1 . After decades of study, the biochemical basis for this group of diseases continues to elude scientists. One obstacle has been the difficulty in establishing specific criteria for diagnosis. This paper reviews case material from 65 @entity1 referred to the Shriver Center for study from January, 1984 to December, 1986. The late-infantile type was the most commonly encountered (35%) with a mean age-of-onset of 3.1 +/- 0.5 yr. The juvenile type was slightly less frequent (32%) with a mean age-of-onset of 7.8 +/- 4 yr. The infantile type ranked third (23%); age-of-onset 11 +/- 4 months) and the adult form of the disease was the least common (10%; age-of-onset 25 +/- 4 yr). Consistent clinical findings were a progressive decline in mental faculties and @entity410 , predominantly of the @entity2045 . Neuroradiological changes of cerebral and cerebellar cortical @entity194 were common when studies were obtained more than a year after clinical onset. Ataxia was a frequent manifestation in the late-infantile and juvenile types whereas @entity3519 was unique to the latter. There was a diversity of ultrastructural findings in skin biopsies between and within types. The absence of findings in a few familial cases necessitated sampling a second tissue such as muscle, particularly when the history was suggestive and urine dolichols were high. Elevated urine @entity56580 levels was a nonspecific but helpful finding.
