Pelizaeus-Merzbacher syndrome: neurocognitive function in a family with carrier manifestations.
A Cajun kindred with Pelizaeus-Merzbacher disease was found to have a p.Q128X mutation in exon 3B of proteolipid protein 1 (PLP1). The affected males were globally delayed in development, nonambulatory, and severely dysarthric. The heterozygous females developed progressive gait disturbances and cognitive deterioration starting in the fourth decade of life. The average IQ (Stanford-Binet Intelligence Scale: 4th Edition (SBFE)) of the carrier females was 54.2, compared to the average IQ of 97.5 in nonaffected relatives. The X-inactivation ratios in the three carrier females were not markedly skewed (55:45, 70:30, and 85:15). The presence of neurological and cognitive deterioration in the three carriers deviates from the usual expectation that carrier expression only occurs in families when males are mildly affected.
Marble
Michael
M
Division of Clinical Genetics, Department of Pediatrics, Children's Hospital of New Orleans, Louisiana State University Health Sciences Center, 200 Henry Clay Avenue, New Orleans, LA 70118, USA. mmarble1@lsuhsc.edu
Voeller
Kytja S
KS
May
Melanie M
MM
Stevenson
Roger E
RE
Schwartz
Charles E
CE
Simensen
Richard J
RJ
D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D020371:Pelizaeus-Merzbacher Disease / Q000175:diagnosis* / Q000235:genetics; D049951:X Chromosome Inactivation