Phenotypes for Nkx2-5 MGI:6294720 MGI Mouse

perinatal lethality, incomplete penetrance ( J:273096 )

• approximately 1/4 of mice die perinatally

abnormal heart morphology ( J:273096 )

• mice exhibit a variety of cardiac malformations that are described below

abnormal left posterior bundle morphology ( J:273097 )

• hearts exhibit an underdeveloped left bundle branch

• acetylcholine activity in left bundle branch is reduced in E18.5 hearts

abnormal atrioventricular node morphology ( J:273097 )

• mice exhibit reduced AV nodal size composed of smaller cardiomyocytes at 4 weeks of age but not at P1

double outlet right ventricle ( J:273096 )

abnormal tricuspid valve morphology ( J:273096 )

• 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

Ebstein's malformation of tricuspid valve ( J:273096 )

tricuspid valve atresia ( J:273096 )

right atrial isomerism ( J:273096 )

• isomerism of the right atrial appendages

abnormal interatrial septum morphology ( J:273096 )

• 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

atrioventricular septal defect ( J:273096 )

• 3 mice exhibit atrioventricular septal defects

enlarged heart ( J:273096 )

abnormal heart ventricle morphology ( J:273096 )

• all newborns exhibit a prominent trabecular layer in ventricular walls indicative of ventricular noncompaction

perimembraneous ventricular septal defect ( J:273096 )

• 80% of mice exhibit perimembranous and/or muscular ventricular septum defects in single or multiple positions

abnormal interventricular septum muscular part morphology ( J:273096 )

• mice exhibit a failure of compaction of the muscular ventricular septum

muscular ventricular septal defect ( J:273096 )

• 80% of mice exhibit perimembranous and/or muscular ventricular septum defects in single or multiple positions

double chambered heart right ventricle ( J:273096 )

abnormal impulse conducting system conduction ( J:273097 )

• electrophysiology studies indicate decreased ventricular effective refractory period

abnormal atrioventricular node conduction ( J:273097 )

• 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

atrioventricular block ( J:273097 )

• mice exhibit first degree atrioventricular (AV) block at 4 weeks, 7 months, and 17 months of age

• mice occasionally exhibit advanced AV block

prolonged PR interval ( J:273097 )

• 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

prolonged QRS complex duration ( J:273097 )

• mice at all ages exhibit a wide QRS, indicating prolonged ventricular conduction times

cardiomyopathy ( J:273096 )