title: Clinical and genetic studies in hereditary spastic paraplegia with thin corpus callosum.
abstract: BACKGROUND
  A complicated form of recessive hereditary spastic paraplegias (HSPs) with thin corpus callosum (TCC) was first described in Japan, and most of the Japanese families showed linkage to chromosome 15q13-15. A recessive HSP locus (SPG11) has also been mapped to chromosome 15q13-15 in Italian and North American families with and without TCC, and it overlaps the region identified in the Japanese families.
  
  
  OBJECTIVE
  To study clinically and genetically 12 Italian families with HSP and TCC.
  
  
  METHODS
  The authors investigated 18 affected and 30 healthy individuals from 12 unrelated Italian families with recessive HSP-TCC. Clinical, neurophysiologic, and neuroradiologic studies were undertaken. All patients were negative for SPG7 mutations. Genetic linkage analyses were carried out with polymorphic DNA markers on 15q13-15.
  
  
  RESULTS
  Five families were consistent with linkage, thus defining a 19.8-cM region between markers D15S1007 and D15S978, encompassing the SPG11 interval. In one consanguineous family, linkage could be firmly excluded, confirming genetic heterogeneity. Two families appeared not linked to the region, but this could not be firmly proved because of the small family size. The remaining four families were uninformative for linkage purposes.
  
  
  CONCLUSIONS
  HSP-TCC is common in Italy. The phenotype is fairly homogeneous and is associated with impaired cognition. There are at least two loci for HSP-TCC, one of which is on chromosome 15q13-15.
authors.affiliation: Department of Neurology and ORL, La Sapienza University, Rome, Italy. carlo.casali@uniroma1.it
authors.forename: C
authors.initials: C
authors.lastname: Casali
authors.forename: E M
authors.initials: EM
authors.lastname: Valente
authors.forename: E
authors.initials: E
authors.lastname: Bertini
authors.forename: G
authors.initials: G
authors.lastname: Montagna
authors.forename: C
authors.initials: C
authors.lastname: Criscuolo
authors.forename: G
authors.initials: G
authors.lastname: De Michele
authors.forename: M
authors.initials: M
authors.lastname: Villanova
authors.forename: M
authors.initials: M
authors.lastname: Damiano
authors.forename: A
authors.initials: A
authors.lastname: Pierallini
authors.forename: F
authors.initials: F
authors.lastname: Brancati
authors.forename: V
authors.initials: V
authors.lastname: Scarano
authors.forename: A
authors.initials: A
authors.lastname: Tessa
authors.forename: F
authors.initials: F
authors.lastname: Cricchi
authors.forename: G S
authors.initials: GS
authors.lastname: Grieco
authors.forename: M
authors.initials: M
authors.lastname: Muglia
authors.forename: M
authors.initials: M
authors.lastname: Carella
authors.forename: B
authors.initials: B
authors.lastname: Martini
authors.forename: A
authors.initials: A
authors.lastname: Rossi
authors.forename: G A
authors.initials: GA
authors.lastname: Amabile
authors.forename: G
authors.initials: G
authors.lastname: Nappi
authors.forename: A
authors.initials: A
authors.lastname: Filla
authors.forename: B
authors.initials: B
authors.lastname: Dallapiccola
authors.forename: F M
authors.initials: FM
authors.lastname: Santorelli
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics; D003241:Consanguinity; D003337:Corpus Callosum / Q000473:pathology*; D005260:Female; D005808:Genes, Recessive; D006239:Haplotypes; D006801:Humans; D007558:Italy; D008126:Lod Score; D008297:Male; D010375:Pedigree; D015419:Spastic Paraplegia, Hereditary / Q000235:genetics* / Q000473:pathology