Mutation analysis of the SPG4 gene in Italian patients with pure and complicated forms of spastic paraplegia.
Mutations in the SPG4 gene are the most common causes of hereditary spastic paraplegia (HSP) accounting for up to 40% of autosomal dominant (AD) forms and 12-18% of sporadic cases. The phenotype associated with HSP due to mutations in the SPG4 gene tends to be pure. There is increasing evidence, however, of patients with complicated forms of spastic paraplegia in which SPG4 mutations were identified. A cohort of 38 unrelated Italian patients with spastic paraplegia, of which 24 had a clear dominant inheritance and 14 were apparently sporadic, were screened for mutations in the SPG4 gene. We identified 11 different mutations, six of which were novel (p.Glu143GlyfsX8, p.Tyr415X, p.Asp548Asn, c.1656_1664delinsTGACCT, c.1688-3C>G and c.*2G>T) and two exon deletions previously reported. The overall rate of SPG4 gene mutation in our patients was 36.8% (14/38); in AD-HSP we observed a mutation frequency of 45.8% (11/24), in sporadic cases the frequency was 21.4% (3/14). Furthermore, we found a mutational rate of 22.2% (2/9) and 41.4% (12/29) in the complicated and pure forms, respectively. The results underlie the importance of genetic testing in all affected individuals.
Magariello
Angela
A
Institute of Neurological Sciences, National Research Council, 87050 Mangone, Cosenza, Italy.
Muglia
Maria
M
Patitucci
Alessandra
A
Ungaro
Carmine
C
Mazzei
Rosalucia
R
Gabriele
Anna Lia
AL
Sprovieri
Teresa
T
Citrigno
Luigi
L
Conforti
Francesca Luisa
FL
Liguori
Maria
M
Gambardella
Antonio
A
Bono
Francesco
F
Piccoli
Tommaso
T
Patti
Francesco
F
Zappia
Mario
M
Mancuso
Michelangelo
M
Iemolo
Franco
F
Quattrone
Aldo
A
D020413:3' Untranslated Regions / Q000235:genetics; D000251:Adenosine Triphosphatases / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002851:Chromatography, High Pressure Liquid; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D017353:Gene Deletion; D005838:Genotype; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense / Q000235:genetics; D010264:Paraplegia / Q000235:genetics*; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000074181:Spastin; D055815:Young Adult
D020413:3' Untranslated Regions; D000251:Adenosine Triphosphatases; D000074181:Spastin; C400283:SPAST protein, human