Phenotypes associated with this allele

• Allele Symbol: Sp4^tm1Krc
• Allele Name: targeted mutation 1, Kenneth R Chien
• Allele ID: MGI:2676622
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Sp4^tm1Krc/Sp4^tm1Krc	involves: 129S4/SvJae * Black Swiss	MGI:2676623

Genotype
MGI:2676623

hm1

• Allelic Composition: Sp4^tm1Krc/Sp4^tm1Krc
• Genetic Background: involves: 129S4/SvJae * Black Swiss

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

mortality/aging

premature death ( J:77375 )

• sudden death in 59% of mutants before 6-8 months of age

• 32% of mutants die at 1 month of age

postnatal lethality, incomplete penetrance ( J:77375 )

• 11% die within 1 week of birth

cardiovascular system

abnormal Purkinje fiber morphology ( J:77375 )

• decrease in the number of distal Purkinje fiber cells

abnormal heartbeat ( J:77375 )

sinus bradycardia ( J:77375 )

• high incidence of sinus bradycardia

ventricular tachycardia ( J:77375 )

• mutants exhibit spontaneous ventricular tachycardia and are highly susceptible to inducible ventricular arrhythmias

absent heartbeat ( J:77375 )

• mutants exhibit asystole and sudden cardiac death

irregular heartbeat ( J:77375 )

ventricular premature beat ( J:77375 )

• all mutants exhibit premature ventricular contractions

abnormal impulse conducting system conduction ( J:77375 )

• sudden cardiac death due to widespread conduction defects and ventricular arrhthymogenesis

• ventricular muscle cells shows an increase in action potential heterogeneity (prolonged action potentials in septal endocardial cells but not in apical epidcardial cells) and a selective decrease of the rapidly activating, delayed rectifier potassium current

atrioventricular block ( J:77375 )

• high incidence of atrioventricular block

sinoatrial block ( J:77375 )

• all mutants exhibit intermittent sinus pauses/sinus blocks

growth/size/body

decreased body size ( J:77375 )

• mice surviving past 6-8 months of age are small in size

muscle

abnormal Purkinje fiber morphology ( J:77375 )

• decrease in the number of distal Purkinje fiber cells