SOMATIC DELETION OF THE 5'-END OF BOTH THE COL4A5 AND COL4A6 GENES INA SPORADIC LEIOMYOMA OF THE ESOPHAGUS

Leiomyomata of the esophagus are sporadic benign tumors of unknown eti ology. We studied a collection of nine tumors for the expression of ex tracellular matrix components and found the same aberrant expression p attern as previously observed in inherited diffuse leiomyomatosis. We demonstrate here the occurrence of a somatic deletion at the COL4A5/CO L4A6 locus at Xq22 in a frozen leiomyoma sample. These data confirm th e hypothesis that the same underlying etiology is responsible for circ umscribed smooth muscle proliferation in sporadic leiomyomata as for d iffuse smooth muscle cell proliferation in inherited diffuse leiomyoma tosis.