**Author details**

association between cases of CL/P and the *ADAMTS20* gene, lengthening the list of candidate

Like any genetic abnormality, the main recommendation in cases of CLP in dogs is that affected individuals should not be crossed, nor should normal couples with affected descendants ever be crossed again. As the majority of oral clefts in dogs appear to be multifactorial or recessive, it should be noted that owners of normal dogs who have had affected offspring are not always willing to follow this recommendation, especially when the dogs have characteristics of their breed that are highly valued. Therefore, if the owners/breeders decide to cross them again, and are sure that the cleft lip or palate is genetic in nature, the risk of recurrence

To avoid autosomal recessive clefts, an important strategy is never to cross individuals that are known to be heterozygotes one with another, such as those that have already had affected offspring. When there is a family history of recessive cleft and the zygosity of an individual is not known, consanguineous unions should be avoided. For X-linked recessive phenotypes, normal female offspring of affected father are all carriers, i.e., heterozygotes, and should not be crossed even when the males are normal. For multifactorial clefts, the main strategy is to avoid crossing dogs that have any relationship. This will reduce the probability of reaching

Always bearing in mind that greater knowledge results in a correct diagnosis, suitable management of each case, and definition of criteria that give consistency to guidelines for prevention of CLP, the first step to expand knowledge is appropriate details when publishing new canine cases, using one of the classifications established in human medicine. This will facilitate international communication between professionals from the different fields in

Breeds, lineages, or families of dogs in which CLP occurs more frequently are a valuable source of information on the molecular biology and genetics of oral clefts. Genome-wide association studies (GWAS) with genotyping using arrays based on single nucleotide polymorphisms (SNP) are powerful means for mapping of regions of interest. The current technologies of next-generation sequencing (NGS), with increasingly robust platforms and increasingly expanded panels, facilitate the identification of candidate genes, allowing studies that con-

It should also be remembered that a chromosomal analysis in syndromic cases should be routine. Analyses with fluorescence *in situ* hybridization (FISH) and comparative genomic hybridization (GCH) may identify chromosomal aberrations and describe new syndromes, as

genes for the etiology of oral clefts in humans.

should be seriously taken into consideration [35].

firm the role of these genes in the etiology of oral clefts.

well as establishing a correlation with human syndromes.

**4.3. Genetic counseling**

160 Designing Strategies for Cleft Lip and Palate Care

the critical threshold [35].

**5. Final considerations**

question.

Enio Moura<sup>1</sup> \* and Cláudia Turra Pimpão2

\*Address all correspondence to: enio.moura@pucpr.br

1 Service of Medical Genetics, Faculty of Veterinary Medicine, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil

2 Department of Animal Science, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
