Mouse Genome Informatics
hm
    Ighmbp2nmd-2J/Ighmbp2nmd-2J
B6.BKS-Ighmbp2nmd-2J/J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
mortality/aging
• at 62 days for males and 76 days for females
• maximum life span is 138 days for females

cardiovascular system
• degenerating and apoptotic
• nuclear blebbing
• secondary valvular insufficiency
• as early as 4-6 weeks of age
• pale, flaccid, enlarged hearts with one or more thrombi
• prolonged P-R interval
• attenuated, sometimes split
• prolonged and attenuated R waves
• decreased lower end systolic blood pressure

nervous system
• frequently show indications of secondary myelin degeneration
• sometimes lacking axons
• axon numbers in quadriceps nerves significantly decrease with age from 3 weeks on, 40% reduction by 12-14 weeks
• significant neuronal loss by 7 weeks in all lumbar ventral roots examined
• 56% of L4 motor axons lost
• numerous dystrophic axons in ventral roots
• most losses are of large axons
• 40% loss of small caliber axons
• vacuolation occurs during the course of myelination or after myelination
• abnormal cytoskeletons
• process of myelination normal
• denervation of motor endplates increases dramatically as motor neuron degeneration progresses

muscle
• degenerating and apoptotic
• nuclear blebbing
• as early as 4-6 weeks of age
• pale, flaccid, enlarged hearts with one or more thrombi
• and fatty infiltration
• severe muscle wasting and hind limb contracture
• centralized nuclei in myocytes
• development of diaphragmatic muscle degeneration occurs late, around 8-14 weeks
• severe diffuse myocyte degeneration and regeneration

behavior/neurological
• much shorter latency to fall when suspended from a wire cage top much shorter latence to fall when suspended from a wire cage top much shorter latence to fall when suspended from a wire cage top much shorter latence to fall when suspended from a wire cage top

respiratory system
• consolidation of lungs
• reduced breathing rate (bradypnea)

growth/size

homeostasis/metabolism
• 3-7 days prior to clearly evident clinical signs of heart disease, total plasma CK and cardiac-specific CK-MB levels in 5- to 9-week-old mice become significantly elevated
• consolidation of lungs
• and fatty infiltration

Mouse Models of Human Disease
OMIM IDRef(s)
Spinal Muscular Atrophy, Distal, Autosomal Recessive, 1; DSMA1 604320 J:92862