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Phenotypes Associated with This Genotype
Genotype
MGI:2176759
Allelic
Composition
Casrtm1Ces/Casrtm1Ces
Genetic
Background
involves: 129X1/SvJ * Black Swiss
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Casrtm1Ces mutation (0 available); any Casr mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• very few homozygotes survive beyond 7 days of age (J:71056)
• most homozygotes are viable at birth but usually die between days 3 and 30 of life (J:29900)

behavior/neurological
• after birth, homozygotes become progressively lethargic
• homozygotes are unable to feed on standard mouse chow pellets and can rarely be weaned
• homozygotes fail to exhibit normal extension of digits, elbows or knee joints
• mutants are unable to elevate their abdomens from the floor
• when flipped onto their backs, homozygotes are unable to return to an upright position

endocrine/exocrine glands
• diffuse hyperplasia of the parathyroid chief cells
• mutant parathyroid glands display diffuse hyperplasia of the parathyroid chief cells

growth/size/body
• by P6, homozygotes display a significant reduction in skeletal size
• by P6, homozygotes weigh significantly less than wild-type
• homozygotes display a significant reduction in growth after P2

hematopoietic system
• the hematocrits of homozygotes are significantly higher than those of heterozygotes or wild-type

homeostasis/metabolism
• relative to heterozygotes, homozygotes display significantly increased PTH concentrations (90-fold increase)
• relative to heterozygotes, homozygotes display significantly increased serum Ca2+ concentrations
• homozygotes display modest elevations of serum Mg2+ concentration
• homozygotes show a modest, but significant, reduction in serum inorganic phosphorus
• in homozygotes, higher hematocrits probably reflect dehydration due to feeding difficulties and/or diuresis induced by hypercalcemia
• the urinary concentration of Ca2+ is abnormally low given the marked elevations in serum Ca2+ levels

renal/urinary system
• the urinary concentration of Ca2+ is abnormally low given the marked elevations in serum Ca2+ levels

skeleton
• homozygotes display a widened zone of hypertrophic chondrocytes in the growth plate
• homozygotes display kyphoscoliosis and bowing of the long bones
• homozygotes frequently exhibit a marked reduction of all bones
• the dry ashed weight is reduced, consistent with osteopenia due to excess osteoid (unmineralized matrix) accumulation
• homozygotes show impaired mineralization of extracellular matrix in both cortical and trabecular bone, and poor mineralization of cartilage
• unexpectedly, 2- to 6-day-old homozygotes exhibit severe rickets rather than the anticipated PTH-mediated skeletal changes
• 2- to 6-day-old newborns display delayed endochondral ossification in the epiphysis and metaphysis of long bones


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
05/19/2026
MGI 6.24
The Jackson Laboratory