pigmentation phenotype

• abnormal melanosome morphology
  • smaller and abnormal melanosomes
  (MGI Ref ID J:80751)

• abnormal melanosome maturation
  • pigmentation appears granular and irregulary deposited
  (MGI Ref ID J:80751)
  • increase in the percentage of both multivesicular and type II/III melanosome forms (immature forms) and a relative lack of elliptical type IV forms
  (MGI Ref ID J:80751)

• abnormal melanosome size
  • progression in size from precursor (type II/III) to mature (type IV) melanosome is abolished, suggesting that melanosome development is arrested at an early stage
  (MGI Ref ID J:80751)

• small melanosome
  (MGI Ref ID J:80751)

hematopoietic system phenotype

• decreased platelet dense granule number
  • Normal - in contrast, the number and size of alpha-granules remains normal
  (MGI Ref ID J:61187)
  • most mutant platelets contain no visible dense bodies, although a small number have one or two
  (MGI Ref ID J:61187)
  • adult homozygotes show a 6-fold decrease in the number of dense bodies (delta granules) per platelet relative to wild-type controls
  (MGI Ref ID J:61187)

• decreased platelet ATP level
  • platelet ATP release is undetectable
  (MGI Ref ID J:61187)

• abnormal platelet dense granule physiology
  • mutant platelets show a marked deficiency of dense body contents
  (MGI Ref ID J:61187)

• decreased platelet aggregation
  • platelet aggregation determined in whole blood by the impedance method in response to collagen (1 or 4 ug/mL) is reduced
  (MGI Ref ID J:61187)

• decreased platelet calcium level
  • loss of dense body electron density suggests a low platelet Ca²⁺ content
  (MGI Ref ID J:61187)

• decreased platelet serotonin level
  • mutant platelet serotonin levels are reduced to ~3% of wild-type levels
  (MGI Ref ID J:61187)

behavior/neurological phenotype

• head tilt
  • others exhibit extreme leaning to one side
  (MGI Ref ID J:61187)
  • some homozygotes display abnormal head tilting only upon handling and close observation
  (MGI Ref ID J:61187)

• abnormal postural reflex
  • ~75% of homozygotes exhibit abnormal postural and balance reflexes with variable severity, suggesting otolith defects
  (MGI Ref ID J:61187)

• impaired balance
  • some homozygotes display balance deficits only upon handling and close observation
  (MGI Ref ID J:61187)
  • others are unable to stand upright
  (MGI Ref ID J:61187)

homeostasis/metabolism phenotype

• decreased platelet serotonin level
  • mutant platelet serotonin levels are reduced to ~3% of wild-type levels
  (MGI Ref ID J:61187)

• increased bleeding time
  • adult homozygotes exhibit significantly increased bleeding times relative to wild-type controls (15.9 +/- 2.9 min versus 1.5 +/- 0.6 min, respectively)
  (MGI Ref ID J:61187)
  • Normal - however, all hematologic parameters, including WBC and RBC counts, hemoglobin, hematocrit, platelet counts and mean platelet volume, are normal
  (MGI Ref ID J:61187)

• abnormal platelet dense granule physiology
  • mutant platelets show a marked deficiency of dense body contents
  (MGI Ref ID J:61187)

• decreased platelet calcium level
  • loss of dense body electron density suggests a low platelet Ca²⁺ content
  (MGI Ref ID J:61187)

• decreased platelet aggregation
  • platelet aggregation determined in whole blood by the impedance method in response to collagen (1 or 4 ug/mL) is reduced
  (MGI Ref ID J:61187)

integument phenotype

• diluted coat color
  • homozygotes display severe coat-color dilution
  (MGI Ref ID J:61187)
  • agouti mice are khaki colored; nonagouti mice resemble homozygous pallid mice
  (MGI Ref ID J:61187)

liver/biliary system phenotype

• abnormal liver physiology
  • in mutant livers, activity levels of alpha-galactosidase are increased by >2-fold relative to wild-type controls
  (MGI Ref ID J:61187)

mammalian phenotype

• respiratory system phenotype
  • Normal - no gross pathologic abnormalities are detected in lung at 10 months of age
  (MGI Ref ID J:61187)

nervous system phenotype

• decreased platelet serotonin level
  • mutant platelet serotonin levels are reduced to ~3% of wild-type levels
  (MGI Ref ID J:61187)

pigmentation phenotype

• diluted coat color
  • homozygotes display severe coat-color dilution
  (MGI Ref ID J:61187)
  • agouti mice are khaki colored; nonagouti mice resemble homozygous pallid mice
  (MGI Ref ID J:61187)

• abnormal retinal pigmentation
  • mutant melanosomes are reduced in number, smaller and less melanized than wild-type
  (MGI Ref ID J:61187)

• hypopigmentation
  • homozygotes display a severe reduction in skin and eye pigment relative to wild-type controls
  (MGI Ref ID J:61187)

• abnormal melanosome morphology
  • mutant melanosomes appear immature and are severely reduced in number in the eye and skin, resulting in severe oculocutaneous albinism
  (MGI Ref ID J:61187)

• decreased eye pigmentation
  • mutant melanosomes are severely reduced in number throughout the retinal pigmented epithelium and choroid layers
  (MGI Ref ID J:61187)

• abnormal choroid pigmentation
  • mutant melanosomes are reduced in number, smaller and less melanized than wild-type
  (MGI Ref ID J:61187)

• abnormal melanogenesis
  • homozygotes display abnormal melanosome formation both quantitatively and qualitatively
  (MGI Ref ID J:61187)

renal/urinary system phenotype

• abnormal kidney physiology
  • in mutant kidneys, activity levels of beta-galactosidase, beta-glucuronidase and alpha-galactosidase are increased by 2.0- to 2.5-fold relative to wild-type controls
  (MGI Ref ID J:61187)

vision/eye phenotype

• abnormal optic choroid morphology
  • homozygotes display a marked reduction in the choroid layer relative to wild-type controls
  (MGI Ref ID J:61187)

• abnormal retinal pigmentation
  • mutant melanosomes are reduced in number, smaller and less melanized than wild-type
  (MGI Ref ID J:61187)

• abnormal choroid pigmentation
  • mutant melanosomes are reduced in number, smaller and less melanized than wild-type
  (MGI Ref ID J:61187)

• decreased eye pigmentation
  • mutant melanosomes are severely reduced in number throughout the retinal pigmented epithelium and choroid layers
  (MGI Ref ID J:61187)

cellular phenotype

• decreased lysosomal enzyme secretion
  • homozygotes display a lysosomal secretion defect resulting in enzyme accumulation in the kidney and liver, but not spleen or platelets
  (MGI Ref ID J:61187)
  • Normal - however, lysosomal protein trafficking studies indicate that the cellular distribution of AP-3 proteins and internalization of lysosomal-associated membrane protein 1(LAMP1) is normal in mutant fibroblasts
  (MGI Ref ID J:61187)

• abnormal vesicle-mediated transport
  • failure of mutant CNO protein to coassemble with pallidin in cultured fibroblasts from homozygous mutant mice indicates that BLOC-1 (biogenesis of lysosome-related organelles complex-1) is disrupted
  (MGI Ref ID J:83960)