Evidence for clinical and genetic heterogeneity in hereditary benign telangiectasia.
BACKGROUND
Telangiectases are abnormal dilatations of end vessels in the subpapillary plexus of the papillary dermis. Hereditary benign telangiectasia (HBT) (OMIM 187260) is a genetic skin disorder, characterized by multiple cutaneous telangiectases appearing in the first years of life in various locations. Several familial cases of HBT have been described displaying autosomal dominant inheritance. In some of the described pedigrees, telangiectases are limited to sun-exposed areas, whereas in others lesions are randomly distributed over the body. The disorder has been previously mapped to a 7Mb interval on chromosome 5q14 (CMC1 locus) in an Italian pedigree with randomly distributed telangiectases.


OBJECTIVE
A large pedigree of HBT with photodistributed lesions is described. We sought to determine whether photodistributed HBT is linked to the CMC1 locus.


METHODS
In all, 35 family members were examined. DNA was extracted from blood and saliva samples. Linkage analysis to CMC1 locus on chromosome 5q14 was screened by using 3 polymorphic markers.


RESULTS
In all, 23 family members were found to have variable numbers of cutaneous radiating macular telangiectases, measuring 1 to 3 cm and distributed over the face, back of the hands, and forearms. HBT in this family is inherited in an autosomal dominant pattern with incomplete penetrance. Linkage to the CMC1 locus was excluded.


CONCLUSIONS
Only one family, although very large, was studied in this project.


CONCLUSIONS
Clinical and genetic heterogeneity is evident in HBT. Photodistributed HBT is not related pathogenically to capillary malformations or to randomly distributed hereditary telangiectases and should be recognized as a separate entity.
Molho-Pessach
Vered
V
Department of Dermatology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
Agha
Ziad
Z
Libster
Diana
D
Lerer
Israela
I
Burger
Ayala
A
Jaber
Saleh
S
Abeliovich
Dvorah
D
Zlotogorski
Abraham
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D002895:Chromosomes, Human, Pair 5; D005260:Female; D005799:Genes, Dominant; D018740:Genetic Heterogeneity; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D019683:Penetrance; D012867:Skin / Q000473:pathology; D013684:Telangiectasis / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*