Mild-onset presentation of Canavan's disease associated with novel G212A point mutation in aspartoacylase gene.
We describe two sisters with a mild-onset variant of Canavan's disease who presented at age 50 and 19 months with developmental delay but without macrocephaly, hypotonia, spasticity, or seizures. Remarkably, both patients had age-appropriate head control, gross motor development, and muscle tone. There were very mild deficits in fine motor skills, coordination, and gait. Both sisters had a history of strabismus, but otherwise vision was normal. The older child showed evidence of mild cognitive and social impairment, whereas language and behavior were normal for age in the infant. Both patients were found to be compound heterozygotes for C914A (A305E) and G212A (R71H) mutations in ASPA. Like all other known ASPA mutations, this previously unknown G212A mutation appears to have low absolute enzyme activity. Nevertheless, it is associated in these patients with an extremely benign phenotype that is highly atypical of Canavan's disease. Biochemical and clinical data were evaluated using a generalized linear mixed model generated from 25 other subjects with Canavan's disease. There were statistically significant differences in brain chemistry and clinical evaluations, supporting a distinct variant of Canavan's disease. Future studies of ASPA enzyme structure and gene regulation in these subjects could lead to a better understanding of Canavan's pathophysiology and improvements in ASPA gene therapy.
Janson
Christopher G
CG
Department of Neurology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Camden, NJ, USA. janson@memorymatters.org
Kolodny
Edwin H
EH
Zeng
Bai-Jin
BJ
Raghavan
Srinivasa
S
Pastores
Gregory
G
Torres
Paola
P
Assadi
Mitra
M
McPhee
Scott
S
Goldfarb
Olga
O
Saslow
Beth
B
Freese
Andrew
A
Wang
D J
DJ
Bilaniuk
Larissa
L
Shera
David
D
Leone
Paola
P
D000328:Adult; D000409:Alanine / Q000235:genetics*; D000581:Amidohydrolases / Q000235:genetics*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D017825:Canavan Disease / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005998:Glycine / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D017354:Point Mutation; D035781:Siblings
D001224:Aspartic Acid; C000179:N-acetylaspartate; D000581:Amidohydrolases; C019751:aspartoacylase; D000409:Alanine; D005998:Glycine