CHROMOSOME-16 MICRODELETION IN A PATIENT WITH JUVENILE NEURONAL CEROID-LIPOFUSCINOSIS (BATTEN-DISEASE)

The gene that is involved in juvenile neuronal ceroid lipofuscinosis ( JNCL), or Batten disease-CLN3-has been localized to 16p12, and the mut ation shows a strong association with alleles of microsatellite marker s D16S298, D16S299, and D16S288. Recently, haplotype analysis of a Bat ten patient from a consanguineous relationship indicated homozygosity for a D16S298 null allele. PCR analysis with different primers on DNA from the patient and his family suggests the presence of a cytogenetic ally undetectable deletion, which was confirmed by Southern blot analy sis. The migodeletion is embedded in a region containing chromosome 16 -specific repeated sequences. However, putative candidates for CLN3, m embers of the highly homologous sulfotransferase gene family, which ar e also present in this region in several copies, were not deleted in t he patient. If the microdeletion in this patient is responsible for Ba tten disease, then we conclude that the sulfotransferase genes are pro bably not involved in JNCL. By use of markers and probes flanking D16S 298, the maximum size of the microdeletion was determined to be simila r to 29 kb. The microdeletion may affect the CLN3 gene, which is expec ted to be in close proximity to D16S298.