Mouse Genome Informatics
hm
    Cyp27b1tm1Star/Cyp27b1tm1Star
involves: 129S1/Sv * 129X1/SvJ
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
endocrine/exocrine glands
• homozygotes display enlarged parathyroid glands (8 weeks), and secondary hyperparathyroidism

growth/size
• homozygotes display a decrease in femur length at 8 weeks
• homozygotes are viable and phenotypically normal at birth but fail to thrive
• homozygotes display a decrease in weight gain from 3-8 weeks of age

homeostasis/metabolism
• at 3 weeks, homozygotes show lack of detectable 1,25(OH)2D3 levels
• at 8 weeks, homozygotes display elevated levels of 25(OH)D3 and very low circulating levels of 24,25(OH)2D3
• homozygotes display increased PTH blood levels as early as weaning
• at 3 weeks of age, homozygotes display hypocalcemia (J:71928)
• supplementation with 1,25(OH)2D3 normalizes the plasma Ca2+ concentration (J:78635)
• the expression of renal Ca2+ transport proteins is significantly down-regulated in agreement with a diminished Ca2+ reabsorption capacity (J:78635)
• high dietary Ca2+ intake restores the expression of renal Ca2+ transport proteins independent of 1,25(OH)2D3 and normalizes serum Ca2+ concentration (J:78635)
• young homozygotes exhibit marked hypophosphatemia which tends towards normal levels at later stages
• homozygotes display elevated serum alkaline phosphatase

skeleton
• homozygotes have expanded growth plates with disorganized cartilage layers
• homozygotes have expanded growth plates with disorganized cartilage layers
• contact radiography of femurs revealed rachitic metaphyseal alterations
• contact radiography of femurs revealed diffuse osteopenia (hypomineralization)
• homozygotes display osteoid (unmineralized matrix) accumulation in trabecular bone due to impaired mineralization (J:71928)
• homozygotes display bone anomalies including rickets and osteomalacia (J:71928)
• high dietary Ca2+ intake does not completely correct bone growth but cures the rickets and osteomalacia and corrects the biomechanical properties of bone tissue (J:90983)
• chronic treatment with 1,25(OH)2D3 is more effective than the high-calcium rescue diet and corrects all aspects of the mutant phenotype (J:90984)

integument
N
• consistent with symptoms of pseudovitamin D deficiency rickets, homozygotes display no alopecia (J:71928)
• homozygotes do not exhibit alopecia (J:71937)

Mouse Models of Human Disease
OMIM IDRef(s)
Vitamin D Hydroxylation-Deficient Rickets, Type 1A; VDDR1A 264700 J:71928 , J:71937 , J:78635 , J:90983 , J:90984