Identification and characterization of a new human cDNA from chromosome 21q22.3 encoding a basic nuclear protein

Area of Science:

• Genetics
• Molecular Biology
• Developmental Biology

Background:

• Congenital heart disease (CHD) affects over 40% of individuals with Down syndrome (DS).
• The chromosomal region 21q22.2-22.3 is implicated in DS-associated CHD.
• Identifying genes in this region is crucial for understanding CHD pathogenesis in DS.

Purpose of the Study:

• To construct a transcriptional map of the Down syndrome CHD region.
• To identify and characterize novel genes within the 21q22.2-22.3 region.
• To investigate the potential role of newly identified genes in DS CHD.

Main Methods:

• Direct cDNA selection using a YAC contig spanning ETS2 to D21S15.
• Utilizing cDNAs synthesized from fetal heart tissues.
• Gene mapping, expression analysis, and protein localization studies.

Main Results:

• Identification and characterization of a new gene, WRB, located at 21q22.3.
• WRB is widely expressed in adult and fetal tissues.
• The WRB gene encodes a basic protein with a tryptophan-rich C-terminus and a nuclear localization signal, predominantly found in the nucleus.

Conclusions:

• The WRB gene has been identified and mapped within the DS CHD critical region.
• WRB protein localizes to the cell nucleus, suggesting a role in nuclear functions.
• Further functional studies of WRB are needed to elucidate its potential role in the pathogenesis of Down syndrome congenital heart disease.