Cloning, sequencing, and analysis of Inv8 chromosome breakpoints associated with recombinant 8 syndrome

Rec8 syndrome (also known as "recombinant 8 syndrome" and "San Luis Valley syndrome") is a chromosomal disorder found in individuals of Hispanic desce nt with ancestry from the San Luis Valley of southern Colorado and northern New Mexico. Affected individuals typically have mental retardation, congen ital heart defects, seizures, a characteristic facial appearance, and other manifestations. The recombinant chromosome is rec(8)dup(8q) inv(8)(p23.1q2 2.1), and is derived from a parental pericentric inversion, inv(8)(p23.1q22 .1). Here we report on the cloning, sequencing, and characterization of the 8p23.1 and 8q22 breakpoints from the inversion 8 chromosome associated wit h Rec8 syndrome. Analysis of the breakpoint regions indicates that they are highly repetitive. Of 6 kb surrounding the 8p23.1 breakpoint, 75% consists of repetitive gene family members-including Alu, LINE, and LTR elements -a nd the inversion took place in a small single-copy region Banked by repetit ive elements. Analysis of 3.7 kb surrounding the 8q22 breakpoint region rev eals that it is 99% repetitive and contains multiple LTR elements, and that the 8q inversion site is within one of the LTR elements.