TY - JOUR
T1 - ALK2 mutation in a patient with Down's syndrome and a congenital heart defect
AU - Joziasse, Irene C.
AU - Smith, Kelly A.
AU - Chocron, Sonja
AU - Van Dinther, Maarten
AU - Guryev, Victor
AU - Van De Smagt, Jasper J.
AU - Cuppen, Edwin
AU - Ten Dijke, Peter
AU - Mulder, Barbara J.M.
AU - Maslen, Cheryl L.
AU - Reshey, Benjamin
AU - Doevendans, Pieter A.
AU - Bakkers, Jeroen
N1 - Funding Information:
We kindly acknowledge the cooperation of the index patient and his family members. Work in JB’s laboratory was partly supported by EU FP6 grant LSHM-CT-2005-018833, EUGeneHeart.
PY - 2011/4
Y1 - 2011/4
N2 - Down's syndrome (DS), resulting from an additional copy of chromosome 21 (trisomy 21), is frequently associated with congenital heart defects (CHDs). Although the increased dosage of chromosome 21 sequences is likely to be part of the etiology of cardiac defects, only a proportion of DS patients exhibit a congenital heart defect (birth prevalence 40-60%). Through a large-candidate gene-sequencing screen in patients with atrioventricular septal defects, substitutions were identified in bone morphogenetic protein (BMP) type I receptor ALK2 and two other genes in a patient with DS and a primum-type atrial septal defect. Structural modeling of the cytoplasmic domain of the ALK2 receptor suggests that H286 is in close proximity to the nucleotide-binding site of the kinase domain. We investigated whether this p.His286Asp substitution altered ALK2 function by using both in vitro as well as in vivo assays. The p.His286Asp variant demonstrated impaired functional activity as measured by BMP-specific transcriptional response assays. Furthermore, mild dominant-interfering activity was observed in vivo compared with wild-type ALK2 as determined by RNA injection into zebrafish embryos. These data indicate that in the context of a DS background, ALK2-mediated reduction of BMP signaling may contribute to CHDs.
AB - Down's syndrome (DS), resulting from an additional copy of chromosome 21 (trisomy 21), is frequently associated with congenital heart defects (CHDs). Although the increased dosage of chromosome 21 sequences is likely to be part of the etiology of cardiac defects, only a proportion of DS patients exhibit a congenital heart defect (birth prevalence 40-60%). Through a large-candidate gene-sequencing screen in patients with atrioventricular septal defects, substitutions were identified in bone morphogenetic protein (BMP) type I receptor ALK2 and two other genes in a patient with DS and a primum-type atrial septal defect. Structural modeling of the cytoplasmic domain of the ALK2 receptor suggests that H286 is in close proximity to the nucleotide-binding site of the kinase domain. We investigated whether this p.His286Asp substitution altered ALK2 function by using both in vitro as well as in vivo assays. The p.His286Asp variant demonstrated impaired functional activity as measured by BMP-specific transcriptional response assays. Furthermore, mild dominant-interfering activity was observed in vivo compared with wild-type ALK2 as determined by RNA injection into zebrafish embryos. These data indicate that in the context of a DS background, ALK2-mediated reduction of BMP signaling may contribute to CHDs.
KW - Down's syndrome
KW - congenital heart defects
KW - gene mutation
UR - http://www.scopus.com/inward/record.url?scp=79952740595&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952740595&partnerID=8YFLogxK
U2 - 10.1038/ejhg.2010.224
DO - 10.1038/ejhg.2010.224
M3 - Article
C2 - 21248739
AN - SCOPUS:79952740595
SN - 1018-4813
VL - 19
SP - 389
EP - 393
JO - European Journal of Human Genetics
JF - European Journal of Human Genetics
IS - 4
ER -