Autosomal dominant familial dyskinesia and facial myokymia: single exome sequencing identifies a mutation in adenylyl cyclase 5.

Abstract

BACKGROUND:

Familial dyskinesia with facial myokymia (FDFM) is an autosomal dominant disorder that is exacerbated by anxiety. In a 5-generation family of German ancestry, we previously mapped FDFM to chromosome band 3p21-3q21. The 72.5-Mb linkage region was too large for traditional positional mutation identification.

OBJECTIVE:

To identify the gene responsible for FDFM by exome resequencing of a single affected individual.

PARTICIPANTS:

We performed whole exome sequencing in 1 affected individual and used a series of bioinformatic filters, including functional significance and presence in dbSNP or the 1000 Genomes Project, to reduce the number of candidate variants. Co-segregation analysis was performed in 15 additional individuals in 3 generations.

MAIN OUTCOME MEASURES:

Unique DNA variants in the linkage region that co-segregate with FDFM.

RESULTS:

The exome contained 23 428 single-nucleotide variants, of which 9391 were missense, nonsense, or splice site alterations. The critical region contained 323 variants, 5 of which were not present in 1 of the sequence databases. Adenylyl cyclase 5 (ADCY5) was the only gene in which the variant (c.2176G>A) was co-transmitted perfectly with disease status and was not present in 3510 control white exomes. This residue is highly conserved, and the change is nonconservative and predicted to be damaging.

CONCLUSIONS:

ADCY5 is highly expressed in striatum. Mice deficient in Adcy5 develop a movement disorder that is worsened by stress. We conclude that FDFM likely results from a missense mutation in ADCY5. This study demonstrates the power of a single exome sequence combined with linkage information to identify causative genes for rare autosomal dominant mendelian diseases.

• Authors: Ying-Zhang Chen, Mark M Matsushita, Peggy Robertson, Mark Rieder, Santhosh Girirajan, Francesca Antonacci, Hillary Lipe, Evan E Eichler, Deborah A Nickerson, Thomas D Bird, Wendy H Raskind
• Journal: Archives of neurology (Arch Neurol) Vol. 69 Issue 5 Pg. 630-5 (May 2012) ISSN: 1538-3687 [Electronic] United States
• PMID: 22782511 (Publication Type: Case Reports, Journal Article, Research Support, American Recovery and Reinvestment Act, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Adenylyl Cyclases
• adenylyl cyclase type V

Topics

• Adenylyl Cyclases (genetics)
• DNA Mutational Analysis
• Dystonic Disorders (complications, genetics)
• Exome
• Facial Nerve Diseases (complications, genetics)
• Family Health
• Female
• Genetic Linkage
• Germany
• Humans
• Male
• Middle Aged
• Mutation, Missense (genetics)
• Polymorphism, Single Nucleotide (genetics)