New DNA testing schemes for the Leonberger

The Kennel Club has approved two new official DNA testing schemes for the Leonberger, for Leonberger Polyneuropathy (LPN2) and Leukoencephalomyelopath (LEMP), following consultation with the breed’s health coordinator on behalf of the breed clubs.

LPN2 is an inherited form of Leonberger polyneuropathy, a severe juvenile-onset neuro-muscular disease which is characterised by progressive exercise intolerance and gait abnormalities leading to wasting of the muscles of the hind limbs and sometimes changes and difficulties in breathing. It is caused by a degradation of myelin, the insulation around nerve fibres.

This is the second genetic region identified as being a major risk factor for Leonberger polyneuropathy (LPN1 is the other). Importantly, while presence of these identified major risk variants can imply the dog is likely to suffer from polyneuropathy, absence does not necessarily mean the dog will not get the disease – it is thought there are further influential genetic variants yet to be discovered.

Nevertheless, knowledge of the genotype of breeding animals (ie the variants they possess at these two genetic locations) can assist breeders in trying to reduce the risk of developing this distressing disease.   

LEMP is a neurodegenerative disorder with similar characteristics as Leonberger polyneuropathy, such as progressive gait abnormalities, abnormalities in limb movements and progressive general lack of coordination. It is also juvenile in onset.

However, unlike polyneuropathy, LEMP is caused by changes to the ‘white matter’ of the central nervous system (brain and spinal cord) rather than changes to the nerve fibres. While not causing pain, the increasing immobility and lack of treatment means that the quality of life of both dogs and owners is reduced.

A mutation strongly associated with LEMP is the basis of this genetic test, the research showing that all dogs with a confirmed diagnosis of LEMP had two copies. However, the researchers noted that not all dogs with two copies of the mutation were affected, implying that there may be some other influence on affectation. Dogs with a single copy, or none, were unaffected.  

The Kennel Club will record the results of these two DNA tests if the owner sends a scanned copy of the certificate by email to our health results team.

To find out which laboratories the Kennel Club is able to record results from, and which labs will send results direct to the Kennel Club, please refer to our Breeds A to Z.