Trichorhinophalangeal syndrome type I: clinical and molecular characterization of 3 members of a family and 1 sporadic case.
BACKGROUND
Trichorhinophalangeal syndrome type I (TRPS I) is a rare autosomal dominant disorder clinically characterized by sparse and slow-growing hair, pear-shaped nose, elongated philtrum, thin upper lip, and bone deformities, in particular, cone-shaped epiphyses of the phalanges. Very recently, the responsible gene TRPS1 has been cloned on human chromosome 8q24.


METHODS
We describe a mother and her 2 daughters and a female patient with a sporadic case of TRPS I. In the familial case, mutation analysis showed an insertional mutation at position 2480 of the TRPS1 gene leading to a premature translational stop. Careful clinical examination showed craniofacial and radiologic features typical of TRPS I, including short stature, in all 3 affected individuals. Additionally, they presented with a receded triangular medio-occipital hairline, which has not been described in TRPS I so far. In the sporadic case, we identified a single base deletion at position 2110 of the TRPS1 gene leading to frameshift and premature translational stop at codon 766. The patient presented with the typical TRPS I phenotype but was of normal stature.


CONCLUSIONS
The TRPS I is characterized by variable clinical expression of the triad of hair, craniofacial, and skeletal abnormalities. New genetic approaches, including mutation analysis, now allow identification of carriers of the TRPS1 gene mutations.
Seitz
C S
CS
Department of Dermatology, University of Würzburg, Josef-Schneider-Str 2, 97080 Würzburg, Germany. cornelia.seitz@mail.uni-wuerzburg.de
Lüdecke
H J
HJ
Wagner
N
N
Bröcker
E B
EB
Hamm
H
H
D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000235:genetics*; D000328:Adult; D001848:Bone Diseases, Developmental / Q000000981:diagnostic imaging / Q000235:genetics; D019465:Craniofacial Abnormalities / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D005385:Fingers / Q000002:abnormalities* / Q000000981:diagnostic imaging; D017353:Gene Deletion; D006580:Genetic Carrier Screening; D006197:Hair / Q000002:abnormalities* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D020125:Mutation, Missense; D011859:Radiography; D013577:Syndrome