Test Detail

DNA panel for the Sphynx and the Devon Rex that combines genetic blood group determination with screening for three hereditary conditions: hypertrophic cardiomyopathy associated with the ALMS1 gene (OMIA002316), polycystic kidney disease (PKD) and genetic myasthenic syndrome (CMS). It covers the cardiac, renal and neuromuscular systems. It is performed from a buccal swab or blood and identifies carrier, affected and predisposed animals. It is especially relevant in the Sphynx, one of the breeds most affected by HCM.

HCM is clinically one of the most prevalent diseases in the Sphynx; the fraction of cases explained by the ALMS1 variant is limited and reliable frequency data are still scarce. PKD is rare in the breed. CMS is exceptional (limited data).

- HCM: heart murmur, gallop rhythm, dyspnoea, syncope, aortic thromboembolism and sudden death
- PKD: renal cysts progressing to chronic kidney failure
- CMS: generalized muscle weakness, exercise fatigability and risk of aspiration pneumonia
- Neonatal isoerythrolysis due to blood group incompatibility

The Sphynx originated in Canada in the 1960s from cats with spontaneous alopecia and was developed through crosses to the Devon Rex, which explains the genetic relatedness between the two breeds. Hypertrophic cardiomyopathy is common in the Sphynx and a variant of the ALMS1 gene was identified through genomic studies. Congenital myasthenic syndrome of the Devon Rex is associated with a variant of the COLQ gene; in the Sphynx the molecular basis of CMS is more recent and less well characterized. Polycystic kidney disease, classically Persian, may appear in breeds related through crosses. The AB blood group system was deciphered in 2007 with the CMAH gene.

- For the ALMS1 variant: avoid breeding carriers together and complement the genetics with annual echocardiograms from an early age
- Do not breed animals positive for PKD1
- In lines with a history of myasthenic syndrome, consult the laboratory about the availability and validity of the test in each breed
- Determine the blood group before mating to prevent neonatal isoerythrolysis

In the Sphynx, HCM is not fully explained by ALMS1: echocardiographic screening remains essential even in genetically negative animals. CMS must be differentiated from acquired myasthenia gravis (anti-acetylcholine receptor antibodies) and from other congenital myopathies. In PKD, ultrasound remains useful because the genetic test only detects the known variant.

1. Bighignoli B et al. 2007, mutaciones de CMAH asociadas al grupo AB felino. BMC Genet. PMID: 17553163
2. Omi T et al. 2016, caracterización molecular de CMAH y el sistema AB felino. PLoS One. PMID: 27755584
3. Gandolfi B et al. 2015, variante de COLQ asociada a miopatía hereditaria del devon rex y el sphynx. Anim Genet. PMID: 26374066
4. Lyons LA et al. 2004, mutación de la enfermedad renal poliquística felina en PKD1. J Am Soc Nephrol. PMID: 15466259
5. Lyons LA 2015, DNA mutations of the cat (revisión). PMID: 25701860