[Outcome of selective mating in the Entlebucher Mountain Dog for reduction of ureteral ectopia]. / Ergebnis der selektiven Verpaarung beim Entlebucher Sennenhund zur Reduktion der ureteralen Ektopie.

INTRODUCTION: The Entlebucher Mountain Dog is predisposed to ureteral ectopia and associated diseases of the urinary tract as well as the kidneys, which can have severe to lethal consequences. Due to the clustered occurrence of clinical signs in 11 % of Entlebucher Mountain dogs in the absence of a genetic test for ureteral ectopia, screening was introduced in 2008 to allow phenotype-based breeding selection. The ureteral orifices of the dogs are visualized by ultrasound and existing urinary retention or urinary incontinence is documented. The diagnostic findings were evaluated centrally with assignment to one of five phenotypes depending on the localization of the ureteral orifices and the renal and ureteral shape. Breeding approval and mating restrictions are the responsibility of the respective breeding associations and predominantly Entlebucher Mountain Dogs with extravesical ectopic ureters and/or clinical signs were excluded from breeding. The effect of phenotype-based selective mating on the incidence of ureteral ectopia and its clinical signs, as well as possible factors influencing the expression of the phenotype, were determined in the birth cohorts after the introduction of screening. Analysis of the data set of 1456 phenotyped Entlebucher Mountain Dogs showed, that at 11 % versus 5 %, males were more frequently assigned to the extravesical phenotype than females. The effect of phenotype-based breeding selection was examined in a subpopulation consisting of phenotyped parents and their offspring (n = 876). The prevalence of the extravesical phenotype decreased from 24 % in the 2005 to 2007 birth cohorts to 1,4 % in the 2015 to 2017 birth cohorts. Since 2015 almost no Entlebucher Mountain Dogs with incontinence, hydroureter or hydronephrosis have been recorded. It was feared that the additional selection measures to control ureteral ectopia in the small Entlebucher Mountain Dog population would intensify the inbreeding increase. However, this has so far remained absent. Therefore, as long as no genetic test is available, it is recommended to continue phenotype-based breeding selection with exclusion of dogs with extravesical ureteral ectopia and/or hydroureter/hydronephrosis/urinary incontinence, while keeping an eye on the development of the inbreeding coefficient.

INTRODUCTION: Le Bouvier de l'Entlebuch est prédisposé à l'ectopie urétérale et aux maladies associées des voies urinaires ainsi que des reins, ce qui peut entraîner des conséquences fatales. En raison de l'apparition de signes cliniques chez 11 % des chiens et en l'absence d'un test génétique pour l'ectopie urétérale, un dépistage a été introduit en 2008 pour permettre une sélection d'élevage basée sur le phénotype. Les orifices urétraux des chiens ont été visualisés par échographie et la rétention ou l'incontinence urinaire existante documentée. Les résultats du diagnostic ont été évalués de manière centralisée avec attribution à l'un des cinq phénotypes en fonction de la localisation des orifices urétéraux ainsi que de la forme des reins et des uretères. L'approbation pour la reproduction et les restrictions d'accouplement relèvent de la responsabilité des associations d'élevage respectives et les bouviers de l'Entlebuch présentant des uretères ectopiques extravésicaux et/ou des signes cliniques ont majoritairement été exclus de la reproduction. L'effet de cet accouplement sélectif basé sur le phénotype sur l'incidence de l'ectopie urétérale et de ses signes cliniques ainsi que les facteurs possibles influençant l'expression du phénotype ont été déterminés dans les cohortes de naissance après l'introduction du dépistage. L'analyse de l'ensemble des données de 1456 Bouviers de l'Entlebuch phénotypés a montré que, à 11 % contre 5 %, les mâles étaient plus fréquemment affectés au phénotype extravésical que les femelles. L'effet de la sélection d'élevage basée sur le phénotype a été examiné dans une sous-population composée de parents phénotypés et de leur progéniture (n = 876). La prévalence du phénotype extravésical est passée de 24 % dans les cohortes de naissance de 2005 à 2007 à 1,4 % dans les cohortes de naissance de 2015 à 2017. Depuis 2015, presque aucun bouvier d'Entlebuch présentant une incontinence, un hydrouretère ou une hydronéphrose n'a été enregistré. Une possible augmentation de la consanguinité due aux mesures de sélection supplémentaires visant à contrôler l'ectopie urétérale ne s'est pas produite. Par conséquent, tant qu'aucun test génétique n'est disponible, il est recommandé de poursuivre la sélection d'élevage basée sur le phénotype avec exclusion des chiens présentant une ectopie urétérale extravésicale et/ou une hydrouretère/hydronéphrose/incontinence urinaire, tout en surveillant l'évolution du coefficient de consanguinité.

Association of missense variants in GDF9 with litter size in Entlebucher Mountain dogs.

In the past two decades, average litter size (ALS) in Entlebucher Mountain dogs decreased by approximately 0.8 puppies. We conducted a GWAS for ALS using the single-step methodology to take advantage of 1632 pedigree records, 892 phenotypes and 372 genotypes (173 662 markers) for which only 12% of the dogs had both phenotypes and genotypes available. Our analysis revealed associations towards the growth differentiation factor 9 gene (GDF9), which is known to regulate oocyte maturation. The trait heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS. Analysis of WGSs revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (-0.75 ± 0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids.

Genome-wide association study and heritability estimate for ectopic ureters in Entlebucher mountain dogs.

An ectopic ureter is a congenital anomaly which may lead to urinary incontinence and without a surgical intervention even to end-stage kidney disease. A genetic component contributes to the development of this anomaly in Entlebucher mountain dogs (EMD); however, its nature remains unclear. Using the Illumina CanineHD bead chip, a case-control genome-wide association study was performed to identify SNPs associated with the trait. Six loci on canine chromosomes 3, 17, 27 and 30 were identified with 16 significantly associated SNPs. There was no single outstanding SNP associated with the phenotype, and the association signals were not close to known genes involved in human congenital anomalies of the kidney or lower urinary tract. Additional research will be necessary to elucidate the potential role of the associated genes in the development of ectopic ureters in the EMD breed.

[Narcolepsy in children]. / Narcolepsia en niños.

INTRODUCTION: Narcolepsy is a neurological disorder characterized by excessive somnolence during the daytime, with recurrent, irresistible episodes of sleepiness. The complete forms are associated with cataplexy, hypnagogic hallucinations and sleep paralysis. The incidence reported in adults is 4 10/10,000. A considerable proportion of adults consider their disorder to have started before the age of 15 years. It is essential to have neurophysiological confirmation of the short period of the onset of REM sleep for diagnosis. CLINICAL CASE: An 11 year old boy with diurnal hypersomnolence, behavior disorder and weight gain. He was evaluated in the Sleep Disorder Unit by polysomnography and the multiple latency test, which confirmed the suspicion of narcolepsy. CONCLUSIONS: Narcolepsy is a disorder which starts during childhood and usually goes unnoticed or is erroneously diagnosed and treated. At the present time there are valid criteria for the identification and diagnosis of children with this disorder. Treatment of these patients should be orientated towards adaptation of the environment to the child and prevention of the psychosocial problems which may be caused by this disorder, in view of the poor response to the drugs used.