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Phenotypes Associated with This Genotype
Genotype
MGI:6294720
Allelic
Composition
Nkx2-5tm1.1Hkas/Nkx2-5+
Genetic
Background
129S2.Cg-Nkx2-5tm1.1Hkas
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Nkx2-5tm1.1Hkas mutation (0 available); any Nkx2-5 mutation (14 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• approximately 1/4 of mice die perinatally

cardiovascular system
• mice exhibit a variety of cardiac malformations that are described below
• hearts exhibit an underdeveloped left bundle branch
• acetylcholine activity in left bundle branch is reduced in E18.5 hearts
• mice exhibit reduced AV nodal size composed of smaller cardiomyocytes at 4 weeks of age but not at P1
• about 50% of mice exhibit abnormal tricuspid valve, including Ebstein's malformation, in which the hinges of tricuspid valve leaflets are displayed towards the apex of the right ventricle, inappropriately delaminated or tethered tricuspid valves, and/or tricuspid valve atresia
• P10 mice exhibit an atrial septal anomaly, with poorly developed flap valve and an increase in the size of the interatrial communication and foamen ovalis, with the maximum length of the septum primum being decreased
• isomerism of the right atrial appendages
• 3 mice exhibit atrioventricular septal defects
• all newborns exhibit a prominent trabecular layer in ventricular walls indicative of ventricular noncompaction
• 80% of mice exhibit perimembranous and/or muscular ventricular septum defects in single or multiple positions
• mice exhibit a failure of compaction of the muscular ventricular septum
• 80% of mice exhibit perimembranous and/or muscular ventricular septum defects in single or multiple positions
• electrophysiology studies indicate decreased ventricular effective refractory period
• electrophysiology studies indicate increased atrioventricular Wenckebach block cycle length, atrioventricular 2:1 conduction block cycle length, and atrioventricular effective refractory period indicating impaired AV node function
• however, sinus nodal function is not affected
• mice exhibit first degree atrioventricular (AV) block at 4 weeks, 7 months, and 17 months of age
• mice occasionally exhibit advanced AV block
• PR interval is prolonged, indicating first degree AV block, is present at 4 weeks, 7 months, and 17 months of age, but not at P1
• mice at all ages exhibit a wide QRS, indicating prolonged ventricular conduction times

muscle
• hearts exhibit an underdeveloped left bundle branch
• acetylcholine activity in left bundle branch is reduced in E18.5 hearts
• mice exhibit reduced AV nodal size composed of smaller cardiomyocytes at 4 weeks of age but not at P1

homeostasis/metabolism
• acetylcholinesterase activity in ventricular trabeculations and left bundle branch is reduced in E18.5 hearts

growth/size/body
• isomerism of the right atrial appendages

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
congenital heart disease DOID:1682 J:273097 , J:273096


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB), Gene Ontology (GO)
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last database update
08/13/2019
MGI 6.14
The Jackson Laboratory