Phenotypes Associated with This Genotype

Genotype
MGI:3811208

• Allelic Composition: Hspg2^tm1.1Soni/Hspg2^tm1.1Soni
• Genetic Background: involves: 129S/SvEv * C57BL/6

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

mortality/aging

premature death ( J:139975 )

• mice die by 24 months of age

nervous system

abnormal neuromuscular synapse morphology ( J:139975 )

• mice exhibit denervation and reinnervation in the neuromuscular junctions (NMJs)

• 96% of mice exhibit NMJ remodeling unlike in wild-type mice

• NMJs cover 58% of the area covered by wild-type NMJs

abnormal endplate potential ( J:139975 )

• mice exhibit prolonged decay time of potentiation of muscle force compared to in wild-type mice

• the twitch/tetanus ratio is 30% higher than in wild-type mice at low frequencies

• however, twitch/tetanus ration is normal at high frequencies

abnormal miniature endplate potential ( J:139975 )

• mice exhibit decreased frequency and prolonged decay of miniature endplate potential compared to in wild-type mice

muscle

abnormal skeletal muscle fiber morphology ( J:139975 )

• no evidence of mononuclear infiltrate or necrotic fibers are present

increased variability of skeletal muscle fiber size ( J:139975 )

• at 6 months of age, mice exhibit variability in skeletal muscle fiber size

centrally nucleated skeletal muscle fibers ( J:139975 )

• at 6 months of age, mice exhibit centralized nuclei in skeletal muscle fibers

abnormal skeletal muscle fiber type ratio ( J:139975 )

• at 6 months of age, mice exhibit a predominance of type 1 skeletal muscle fibers

abnormal muscle electrophysiology ( J:139975 )

• skeletal muscles exhibit spontaneous muscle activity at rest on an electromyogram unlike in wild-type mice

• however, no spontaneous activity is observed in the diaphragm

skeleton

abnormal joint morphology ( J:139975 )

• mice exhibit hip dysplasia

chondrodystrophy ( J:139975 )

growth/size/body

decreased body weight ( J:139975 )

• mice exhibit a decrease in body weight compared to in Hspg2^tm1.1Soni homozygotes and wild-type mice

decreased body length ( J:139975 )

• mice are 15% shorter than wild-type mice

behavior/neurological

abnormal behavior ( J:139975 )

• at 2 months of age, mice display stiffened flexion of the hindlimbs when suspended by the tail, unlike in wild-type mice, that is more severe than in Hspg2^tm1.1Soni homozygotes

• at 6 months of age 54% of mice exhibit strong stiffened flexion of the hindlimbs and 31% mild stiffened flexion of the hindlimbs when suspended by the tail

vision/eye

delayed eyelid opening ( J:139975 )

• at 2 months of age, mice exhibit a delay in eyelid opening that is more severe than in Hspg2^tm1.1Soni homozygotes

• at 6 months of age, 54% of mice have constantly closed eyes

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Schwartz-Jampel syndrome 1		DOID:0090005	OMIM:255800	J:139975