Alternating hemiplegia of childhood 2 (AHC2)

Alternating hemiplegia of childhood 2 (AHC2) is a rare syndrome with an autosomal dominant inheritance characterized by infantile onset of episodic hemi-or quadriplegia.  AHC2 (MIM 614820) is caused by mutations in the ATP1A3 gene. ATP1A3 is also involved in Rapid-onset dystonia-parkinsonism (RDP) (MIM 128235) and Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) syndrome (MIM 601338).

 

Gene

Gene Product

Locus

Inheritance

OMIM number

Reference sequence

ATP1A3

ATPase, Na+/K+ TRANSPORTING, ALPHA-3 POLYPEPTIDE

19q13.2

Autosomal Dominant

182350

NC_000019.9 ,

NM_152296.4

Procedure:  A request for confirmation of a diagnosis of Alternating hemiplegia of childhood 2 will involve analysis of the ATP1A3 gene using standard sequence analysis. When the diagnosis is not so clear an exome sequencing using the gene panel intellectual disability can be requested. ATP1A3 is part of the gene panel intellectual disability and/or congenital abnormalities.

 

Gene

Request form

Techniques

ATP1A3

Molecular genetic testing

Sequence analysis of the entire coding region (exons 1 to 23), including intron/exon junctions.

Gene panel intellectual disability and/or congenital abnormalities

Exoomsequencing (Dutch)

Sequence analysis of the coding and flanking introns sequences using next generation sequencing.

Detection ratio: 85%1

 

1)      Panagiotakaki E, De Grandis E, Stagnaro M, Heinzen EL, Fons C, Sisodiya S, de Vries B, Goubau C, Weckhuysen S, Kemlink D, Scheffer I, Lesca G, Rabilloud M, Klich A, Ramirez-Camacho A, Ulate-Campos A, Campistol J, Giannotta M, Moutard ML, Doummar D, Hubsch-Bonneaud C, Jaffer F, Cross H, Gurrieri F, Tiziano D, Nevsimalova S, Nicole S, Neville B, van den Maagdenberg AM, Mikati M, Goldstein DB, Vavassori R, Arzimanoglou A, et al. Clinical profile of patients with ATP1A3 mutations in alternating hemiplegia of childhood-a study of 155 patients. Orphanet J Rare Dis. 2015;10:123.


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