del(8)(q24.11q24.13)

Langer-Giedion Syndrome

Tricho-Rhino-Phalangeal Syndrome Type II

Epidemiology and Etiology:

· Deletion involving TRPS1, EXT1 and several other genes

· TRPS1 is gene for tricho-rhino-pharyngeal (TRP) syndrome type I

· EXT1 deletion causes exostoses

· May arise on chromosome 8 of either parent

· Autosomal dominant

· Almost all cases are sporadic

Common sites:

·

Gross features:

· Distinctive facies including small mandible, bulbous nose, others

· microcephaly

· Sparse hair

· Redundant skin

· Cartilaginous exostoses (distinctive feature from TRPS type I

· Extremities of long bones

· Cone-shaped phalangeal epiphyses

· Growth retardation

· hypotonia

Histologic features:

·

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

·

Other features:

· Intellectual deficit

· Hearing problems

· Frequent respiratory infections

References:

· Gardner RJM, Sutherland GR. Chromosome Abnormalities and Genetic Counseling. 2nd ed. Oxford University Press, USA; 1996:496.

· www.orpha.net (accessed 2010)