NEW YORK, Apr 27 (Reuters Health) - A scan of the entire human genetic
sequence has identified a small area of chromosome 1 that is linked to
schizophrenia in 22 families.
"Family, twin, and adoption studies have demonstrated that schizophrenia is
predominantly genetic, with a high (inheritance rate)," according to Linda
Brzustowicz from Rutgers University in Newark, New Jersey and associates.
Previous scans of the whole genome have found only one linkage to
schizophrenia, on chromosome 13, the authors note.
For their study, the researchers selected 22 families in which members of
several generations were affected by schizophrenia, thereby increasing the
chances of identifying a genetic source of the condition. Their findings are
reported in the April 28th issue of Science.
Using statistical tests of linkage, the scientists linked a small portion of
chromosome 1, in an area whose official map location is 1q21-1q22, to
schizophrenia in these families.
Earlier studies suggested possible linkages of schizophrenia to more distant
parts of chromosome 1, but none has linked 1q21-1q22 to the disease, the
researchers note.
Additional tests in these families confirmed a link to chromosome 13, but
the association was much weaker, the report indicates.
Given the complexity of the disease, the unequivocal linkage of
schizophrenia to this single chromosome site was somewhat unexpected, the
researchers say. Multiple genetic sites are almost certainly involved in the
development of schizophrenia, they explain.
The strong association of the disease to this small area of chromosome 1
should enable scientists to identify the exact gene involved in these families'
schizophrenia, the authors suggest.
"It is hoped that better understanding of the genetic factors involved in
this common, devastating disorder will lead to earlier and more effective
interventions," they conclude.
