Abstract
A case of Larsen synrome was studied as to the recurrent chromosome breaks (fragile sites). The lymphocytes in the peripheral blood were cultured in a folic acid deficient (FA-MEM) medium supplemented with 10% fetal bovine serum. Air-dried chromosome preparation was stained by the trypsin giemsa method.
The presence of the fragile site chromosome in 2% or more of the metaphases was judged as positive.
The patient is a 9-year-old girl and mentally retarded.
She was characterized by multiple congenital dislocations of the knees, and had a depressed nasal bridge, wide-spaced eyes, abnormal segmentation of the spine and cylind-rical-shaped fingers.
Cytogenetic investigations showed the karyotype 46, XX.
We found chromosome gaps (16 q 22 or 23, D-group: 13 q 11 or 12).
Frequency of the chromosome gaps were 16 q 22 or 23: 2%, 13 q 11 or 12: 10%.
It is possible that the patients with Larsen syndrome may have mutant genes (fragile sites).
