mortality/aging
• 44% of homozygotes die before or at weaning
• death is attributed to poor nutritional status
• homozygotes that survive weaning appear normal thereafter, despite smaller size and lower body weight
|
behavior/neurological
• homozygotes frequently have difficulties in feeding during the first 2 weeks of life
|
growth/size/body
• at birth, homozygotes are noticeably smaller than wild-type littermates
|
• at birth, homozygotes exhibit a significantly reduced body weight relative to wild-type controls (1.49 0.08 g vs 1.89 0.12 g)
|
• homozygotes remain significantly smaller than wild-type littermates for at least 4 months after birth
|
• homozygotes maintain a significantly lower body weight for at least 4 months after birth
|
homeostasis/metabolism
• at 2-3 months of age, serum PTH levels are appropriately decreased in response to hypercalciuria
|
• serum calcium levels are slightly but significantly increased at all ages examined, in an age-independent manner
|
• at 1-7 months of age, serum inorganic phosphate (Pi) levels are significantly reduced
|
• young homozygotes display significantly higher serum ALPase activity relative to age-matched wild-type and heterozygous mice
• however, by 4 months of age, serum ALPase activity is comparable in all three genotypes
|
• at 1 month of age, the urine calcium/creatinine ratio and the fractional excretion index for calcium (FEICa) are significantly increased
|
• at 1-3 months of age, homozygotes exhibit an appropriate adaptive increase in serum 1,25(OH)2D levels in response to hypophosphatemia
|
• at 1 month of age, the urine Pi/creatinine ratio and the fractional excretion index for Pi (FEIPi) are strikingly increased
|
renal/urinary system
N |
• homozygotes show no evidence for amino aciduria, glycosuria, or proteinuria, indicating that the renal inorganic phosphate leak is not due to a generalized tubulopathy
|
• at 1 month of age, the urine calcium/creatinine ratio and the fractional excretion index for calcium (FEICa) are significantly increased
|
• at 1 month of age, the urine Pi/creatinine ratio and the fractional excretion index for Pi (FEIPi) are strikingly increased
|
skeleton
N |
• homozygotes do not exhibit rickets or osteomalacia
|
• poor initial development of cancellous bone
• by 45 days of age, the number metaphyseal trabeculae exceeded that in wild-type
|
• initial impairment of secondary ossification in the epiphysis observed at 21 days of age
• by 45 days of age, the skeletal phenotype had reversed and overcompensated
|
muscle
• homozygotes display apparent muscle weakness during the first 2 weeks of life
|
reproductive system
• homozygotes display reduced reproductive ability relative to wild-type and heterozygous controls
|
Mouse Models of Human Disease |
DO ID | OMIM ID(s) | Ref(s) | |
hereditary hypophosphatemic rickets with hypercalciuria | DOID:0050947 |
OMIM:241530 |
J:47637 |