# 611820

LONG QT SYNDROME 11; LQT11


Phenotype-Gene Relationships

Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
Gene/Locus Gene/Locus
MIM number
7q21.2 ?Long QT syndrome 11 611820 AD 3 AKAP9 604001
Clinical Synopsis
 
Phenotypic Series
 

INHERITANCE
- Autosomal dominant
CARDIOVASCULAR
Heart
- Prolongation of corrected QT interval
- Syncope
MISCELLANEOUS
- Based on report of 1 family (last curated April 2017)
MOLECULAR BASIS
- Caused by mutation in the A-kinase anchor protein 9 gene (AKAP9, 604001.0001)

TEXT

A number sign (#) is used with this entry because of evidence that long QT syndrome-11 (LQT11) is caused by heterozygous mutation in the gene encoding the A-kinase anchor protein-9 (AKAP9; 604001) on chromosome 7q21. One such family has been reported.

For a discussion of genetic heterogeneity of long QT syndrome, see LQT1 (192500).


Description

Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death (Jongbloed et al., 1999).


Molecular Genetics

In a 13-year-old Caucasian girl with long QT syndrome, who was negative for mutation in the known LQT genes, Chen et al. (2007) identified heterozygosity for a ser1570-to-leu (S1570L; 604001.0001) substitution in the AKAP9 gene. The patient's father and 2 sisters had also ECG-diagnosed LQT syndrome; 1 affected sister, with a QTc of 480ms, agreed to testing and was found to carry the mutation, which was not found in 1,320 reference alleles.


REFERENCES

  1. Chen, L., Marquardt, M. L., Tester, D. J., Sampson, K. J., Ackerman, M. J., Kass, R. S. Mutation of an A-kinase-anchoring protein causes long-QT syndrome. Proc. Nat. Acad. Sci. 104: 20990-20995, 2007. [PubMed: 18093912, images, related citations] [Full Text]

  2. Jongbloed, R. J. E., Wilde, A. A. M., Geelen, J. L. M. C., Doevendans, P., Schaap, C., Van Langen, I., van Tintelen, J. P., Cobben, J. M., Beaufort-Krol, G. C. M., Geraedts, J. P. M., Smeets, H. J. M. Novel KCNQ1 and HERG missense mutations in Dutch long-QT families. Hum. Mutat. 13: 301-310, 1999. [PubMed: 10220144, related citations] [Full Text]


Creation Date:
Marla J. F. O'Neill : 2/25/2008
carol : 04/23/2017
carol : 07/22/2015
alopez : 6/12/2014
carol : 1/14/2011
wwang : 2/26/2008

# 611820

LONG QT SYNDROME 11; LQT11


ORPHA: 101016, 768;   DO: 0110652;  


Phenotype-Gene Relationships

Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
Gene/Locus Gene/Locus
MIM number
7q21.2 ?Long QT syndrome 11 611820 Autosomal dominant 3 AKAP9 604001

TEXT

A number sign (#) is used with this entry because of evidence that long QT syndrome-11 (LQT11) is caused by heterozygous mutation in the gene encoding the A-kinase anchor protein-9 (AKAP9; 604001) on chromosome 7q21. One such family has been reported.

For a discussion of genetic heterogeneity of long QT syndrome, see LQT1 (192500).


Description

Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death (Jongbloed et al., 1999).


Molecular Genetics

In a 13-year-old Caucasian girl with long QT syndrome, who was negative for mutation in the known LQT genes, Chen et al. (2007) identified heterozygosity for a ser1570-to-leu (S1570L; 604001.0001) substitution in the AKAP9 gene. The patient's father and 2 sisters had also ECG-diagnosed LQT syndrome; 1 affected sister, with a QTc of 480ms, agreed to testing and was found to carry the mutation, which was not found in 1,320 reference alleles.


REFERENCES

  1. Chen, L., Marquardt, M. L., Tester, D. J., Sampson, K. J., Ackerman, M. J., Kass, R. S. Mutation of an A-kinase-anchoring protein causes long-QT syndrome. Proc. Nat. Acad. Sci. 104: 20990-20995, 2007. [PubMed: 18093912] [Full Text: https://doi.org/10.1073/pnas.0710527105]

  2. Jongbloed, R. J. E., Wilde, A. A. M., Geelen, J. L. M. C., Doevendans, P., Schaap, C., Van Langen, I., van Tintelen, J. P., Cobben, J. M., Beaufort-Krol, G. C. M., Geraedts, J. P. M., Smeets, H. J. M. Novel KCNQ1 and HERG missense mutations in Dutch long-QT families. Hum. Mutat. 13: 301-310, 1999. [PubMed: 10220144] [Full Text: https://doi.org/10.1002/(SICI)1098-1004(1999)13:4<301::AID-HUMU7>3.0.CO;2-V]


Creation Date:
Marla J. F. O'Neill : 2/25/2008

Edit History:
carol : 04/23/2017
carol : 07/22/2015
alopez : 6/12/2014
carol : 1/14/2011
wwang : 2/26/2008