Mouse Genome Informatics
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    Acvr2btm1Enl/Acvr2btm1Enl
either: (involves: 129S4/SvJae) or (involves: 129S4/SvJae * C57BL/6J)
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
mortality/aging
• Background Sensitivity: on the 129S4 background, no homozygotes are seen at weaning
• on a mixed 129S4 and C57BL/6 background, 30% survive past weaning and these are viable and fertile

cardiovascular system
• abnormal looping of the descending aorta on a 129S4 background, with 51% showing looping toward the right instead of the left as in wild-type
• Background Sensitivity: all mice on the 129S4 background and 60% on the mixed 129S4 and C57BL/6 background exhibit defects in the patterning of the outflow tract
• the two great arteries are located in abnormal positions
• the aorta arises from the anterior-most position of the heart and the pulmonary trunk is located posterior to and on either the left or right side of the aorta
• the pulmonary trunk and the aorta are in parallel positions without crossing over each other
• on the 129S4 background, the apex of the heart points in a random direction instead of to the left
• some mutants show left superior vena cava connected to the left atrium
• 30% of homozygotes on the 129S4 background show right atrial isomerism
• Background Sensitivity: seen in 30% of mice on a 129S4 background and a lower frequency in mice on the mixed 129S4 and C57BL/6 background
• Background Sensitivity: seen in 30% of mice on a 129S4 background

hematopoietic system
• abnormally shaped spleen

homeostasis/metabolism

renal/urinary system
• Background Sensitivity: 80% and 53% of homozygotes on the 129S4 and the mixed 129S4 and C57BL/6 backgrounds, respectively, show renal hypoplasia
• exhibit a spectrum of renal abnormalities including uni- or bilateral agenesis
• exhibit a spectrum of renal abnormalities including uni- or bilateral agenesis

respiratory system
• Background Sensitivity: 100% of homozygotes exhibit right pulmonary isomerism (RPI) and cardiac malformations on the 129S4 background, while on the mixed 129S4 and C57BL/6 background, all homozygotes with outflow tract defects show RPI, whereas all viable mice have normal hearts and lungs
• the left lung has four lobes, in mirror image to the right lung
• morphology and branching patterns of the bronchi appear to be bilaterally symmetric, and in most cases, both bronchi are eparterial

skeleton
• have 9 vertebrosternal ribs and 7 free ribs
• frequently the first rib (T1) on vertebra 8 (V8) is fused to the second rib (T2) on the ventral side and connected to the sternum at the T2 position
• have 16, instead of 13, thoracic vertebrae, displaying the C7/T16/L6 vertebral configuration
• shape of the dorsal side of V9 (T2) vertebra is similar to that of V8 (T1) of wild-type
• the largest spinous process, a characteristic of V9 (T2) vertebra, is present at V10 (T3)
• the transition of the spinous process shape occurs at V18 and V20, instead of at V16 and V17, as in wild-type
• spinous process of V19 pints in the posterior direction although its shape looks similar to V17
• last pair of thoracic ribs are attached to V23 instead of V20

liver/biliary system
• although the liver has the same number and patterns of lobes as wild-type, the shape of some lobes is slightly altered

growth/size/body
• some mutants show left superior vena cava connected to the left atrium
• 30% of homozygotes on the 129S4 background show right atrial isomerism
• Background Sensitivity: 100% of homozygotes exhibit right pulmonary isomerism (RPI) and cardiac malformations on the 129S4 background, while on the mixed 129S4 and C57BL/6 background, all homozygotes with outflow tract defects show RPI, whereas all viable mice have normal hearts and lungs
• the left lung has four lobes, in mirror image to the right lung

immune system
• abnormally shaped spleen

Mouse Models of Human Disease
OMIM IDRef(s)
Heterotaxy, Visceral, 4, Autosomal; HTX4 613751 J:42018
Right Atrial Isomerism; RAI 208530 J:42018