Phenotypes Associated with This Genotype

Genotype
MGI:3783638

• Allelic Composition: Lama2^dy/Lama2^dy
• Genetic Background: involves: 129P1/Re

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

mortality/aging

premature death ( J:13125 )

• most homozygotes die between 1 and 6 months of age

muscle

abnormal sarcolemma morphology ( J:13125 )

• unusual proliferation of sarcolemmal nuclei

abnormal skeletal muscle fiber morphology ( J:13125 )

• in contrast to wild-type, space between fibers is increased and an increase in interstitial tissue is observed

• in some cases, fat cells are found between fibers

• unusual proliferation of nuclei both within and between the fibers

• affected fibers appear rounded rather than polygonal in transverse section

increased variability of skeletal muscle fiber size ( J:13125 )

• individual fibers exhibit size variations

centrally nucleated skeletal muscle fibers ( J:13125 )

• some fibers, although otherwise normal, contain long chains of centrally, rather than peripherally, located nuclei

dystrophic muscle ( J:13125 )

• muscular atrophy proceeds from hind quarters to axial and forelimb musculature

progressive muscle weakness ( J:13125 )

• mild paralysis is first observed at 3.5 week and progresses to hindlimb dragging by 8 weeks

• eventually there is a complete loss of locomotor function and premature death

skeleton

kyphosis ( J:13125 )

• observed at 8 weeks

behavior/neurological

ataxia ( J:13125 )

• ataxia with occasional unilateral paresis is first observed at 3.5 weeks of age

paresis ( J:13125 )

• unilateral paresis begins at 3.5 weeks progressing to bilateral paresis

• paresis is accompanied by spasmodic flexion and flaccid extension in hindlimbs

• mild paralysis is first observed at 3.5 weeks and progresses to hindlimb dragging by 8 weeks

abnormal sexual interaction ( J:13125 )

• failure to mate putatively due to physical disability

• gonad morphology is normal

growth/size/body

decreased body weight ( J:13125 )

• by two weeks of age, body weight is less than wildtype

• weight difference continues through out lifespan

cachexia ( J:13125 )

• cachexia as well as thinning and ruffling of fur is observed by 8 weeks

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
congenital merosin-deficient muscular dystrophy 1A		DOID:0110636	OMIM:607855	J:13125