Encyclopedia of the mouse genome III. October 1993. Mouse chromosome 19

Screening for autosomal recessive and X-linked conditions during pregnancy and preconception: a practice resource of the American College of Medical Genetics and Genomics (ACMG)

Carrier screening began 50 years ago with screening for conditions that have a high prevalence in defined racial/ethnic groups (e.g., Tay-Sachs disease in the Ashkenazi Jewish population; sickle cell disease in Black individuals). Cystic fibrosis was the first medical condition for which panethnic screening was recommended, followed by spinal muscular atrophy. Next-generation sequencing allows low cost and high throughput identification of sequence variants across many genes simultaneously. Since the phrase "expanded carrier screening" is nonspecific, there is a need to define carrier screening processes in a way that will allow equitable opportunity for patients to learn their reproductive risks using next-generation sequencing technology. An improved understanding of this risk allows patients to make informed reproductive decisions. Reproductive decision making is the established metric for clinical utility of population-based carrier screening. Furthermore, standardization of the screening approach will facilitate testing consistency. This practice resource reviews the current status of carrier screening, provides answers to some of the emerging questions, and recommends a consistent and equitable approach for offering carrier screening to all individuals during pregnancy or preconception.

Chromosomal assignment of the genes for proprotein convertases PC4, PC5, and PACE 4 in mouse and human

The genes for three subtilisin/kexin-like proprotein convertases, PC4, PC5, and PACE4, were mapped in the mouse by RFLP analysis of a DNA panel from a (C57BL/6JEi x SPRET/Ei)F1 x SPRET/Ei backcross. The chromosomal locations of the human homologs were determined by Southern blot analysis of a DNA panel from human-rodent somatic cell hybrids, most of which contained a single human chromosome each. The gene for PC4 (Pcsk4 locus) mapped to mouse chromosome 10, close to the Adn (adipsin, a serine protease) locus and near the Amh (anti-müllerian hormone) locus; in human, the gene was localized to chromosome 19. The gene for PC5 (Pcsk5 locus) mapped to mouse chromosome 19 close to the Lpc1 (lipocortin-1) locus and, in human, was localized to chromosome 9. The gene for PACE4 (Pcsk6 locus) mapped to mouse chromosome 7, at a distance of 13 cM from the Pcsk3 locus, which specifies furin, another member of this family of enzymes previously mapped to this chromosome. This is in concordance with the known close proximity of these two loci in the homologous region on human chromosome 15q25-qter. Pcsk3 and Pcsk6 mapped to a region of mouse chromosome 7 that has been associated cytogenetically with postnatal lethality in maternal disomy, suggesting that these genes might be candidates for imprinting.

Mapping of human and murine genes for latent TGF-beta binding protein-2 (LTBP2)

A novel gene, isolated because of structural similarities to fibrillin, was called LTBP2 when its 4.6-kb transcript was found to encode a protein sequence related to the latent TGF-beta binding protein (LTBP1), which is encoded on human chromosome (Chr) 2, region p12-q22. We have assigned the human and murine LTBP2 loci to regions of conserved synteny on human Chr 11 and mouse Chr 19. By PCR analysis of somatic cell hybrid DNA and fluorescence in situ hybridization, LTBP2 was mapped to human Chr band 11q12 and Ltbp2 to mouse Chr band 19B. Differences between inbred strains were discovered by single-strand conformation analysis of PCR products from the 3' untranslated region. Analysis of BXD and AKXL recombinant inbred strains have placed Ltbp2 between D19Rp19 and Ly10 on proximal mouse Chr 19.

The mouse Fau gene: genomic structure, chromosomal localization, and characterization of two retropseudogenes

The Fau gene is the cellular homolog of the fox sequence of the Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV). FBR-MuSV acquired the Fau gene by transduction in a transcriptional orientation opposite to that of the genomic Fau gene. The genomic structure of the mouse Fau gene (MMFAU) and its upstream elements have been determined and are similar to those of the human FAU gene. The gene consists of five exons and is located on chromosome 19. The first exon is not translated. The promoter region has no well-defined TATA box but contains the polypyrimidine initiator flanked by regions of high GC content (65%) and shows all of the characteristics of a housekeeping gene. The 5' end of the mRNA transcript was determined by 5' RACE analysis and is located, as expected, in the polypyrimidine initiator site. Furthermore, the sequences of two retropseudogenes (Fau-ps1 and Fau-ps2) are reported. Both pseudogenes are approximately 75% identical to the Fau cDNA, but both are shorter due to a deletion at the 5' end and do not encode a functional protein. Fau-prs is interrupted by an AG-rich region of about 350 bp within the S30 region of the Fau cDNA. Fau-ps1 was localized on chromosome 1 and Fau-ps2 on chromosome 7.

Assignment of a locus for mouse lung tumor susceptibility to proximal chromosome 19

Previous studies have hypothesized that at least three genetic loci contribute to differences in pulmonary adenoma susceptibility between mouse strains A/J and C57BL/6J. One gene that may confer susceptibility to lung tumorigenesis is the Kras protooncogene. To identify other relevant loci involved in this polygenic trait, we determined tumor multiplicity in 56 randomly chosen N-ethyl-N-nitrosourea-treated (A/J x C57BL/6J) N1 x C57BL/6 backcross (AB6N2) progeny and correlated it with genotypes at 77 microsatellite markers spanning the genome. A correlation of lung tumor multiplicity phenotypes with genotypes of microsatellite markers on distal Chromosome (Chr) 6 in the Kras region (Pas1) was confirmed, and a new region on Chr 19 (designated Pas3) was identified that also contributes to susceptibility. Linkage analysis on Chr 19 with 270 AB6N2 mice localized the region flanked by D19Mit42 and D19Mit19 that is most closely associated with lung tumor susceptibility. The Pas3 locus may be an enhancer of the susceptibility locus on Chr 6.

Molecular map of chromosome 19 including three genes affecting bleeding time: ep, ru, and bm

The mouse ruby eye (ru) and pale ear (ep) pigment dilution genes cause platelet storage pool deficiency (SPD) and prolonged bleeding times. The brachymorphic (bm) gene, in addition to causing skeletal abnormalities, is also associated with prolonged bleeding times. All three hemorrhagic genes are found within 10 cM on Chromosome (Chr) 19. In this study, 15 microsatellite markers and five cDNAs, spanning 21 cM of Chr 19, were mapped in relation to the bm, ep, and ru genes in 457 progeny of an interspecific backcross utilizing the highly inbred strain PWK derived from the Mus musculus musculus species. Several markers were found to be closely linked to the three genes and should be useful as entry points in their eventual molecular identification.