Novel Brown Coat Color (Cocoa) in French Bulldogs Results from a Nonsense Variant in HPS3

Brown or chocolate coat color in many mammalian species is frequently due to variants at the B locus or TYRP1 gene. In dogs, five different TYRP1 loss-of-function alleles have been described, which explain the vast majority of dogs with brown coat color. Recently, breeders and genetic testing laboratories identified brown French Bulldogs that did not carry any of the known mutant TYRP1 alleles. We sequenced the genome of a TYRP1+/+ brown French Bulldog and compared the data to 655 other canine genomes. A search for private variants revealed a nonsense variant in HPS3, c.2420G>A or p.(Trp807*). The brown dog was homozygous for the mutant allele at this variant. The HPS3 gene encodes a protein required for the correct biogenesis of lysosome-related organelles, including melanosomes. Variants in the human HPS3 gene cause Hermansky-Pudlak syndrome 3, which involves a mild form of oculocutaneous albinism and prolonged bleeding time. A variant in the murine Hps3 gene causes brown coat color in the cocoa mouse mutant. We genotyped a cohort of 373 French Bulldogs and found a strong association of the homozygous mutant HPS3 genotype with the brown coat color. The genotype-phenotype association and the comprehensive knowledge on HPS3 function from other species strongly suggests that HPS3:c.2420G>A is the causative variant for the observed brown coat color in French Bulldogs. In order to clearly distinguish HPS3-related from the TYRP1-related brown coat color, and in line with the murine nomenclature, we propose to designate this dog phenotype as "cocoa", and the mutant allele as HPS3co.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:11

Enthalten in:

Genes - 11(2020), 6 vom: 09. Juni

Sprache:

Englisch

Beteiligte Personen:

Kiener, Sarah [VerfasserIn]
Kehl, Alexandra [VerfasserIn]
Loechel, Robert [VerfasserIn]
Langbein-Detsch, Ines [VerfasserIn]
Müller, Elisabeth [VerfasserIn]
Bannasch, Danika [VerfasserIn]
Jagannathan, Vidhya [VerfasserIn]
Leeb, Tosso [VerfasserIn]

Links:

Volltext

Themen:

Canis lupus familiaris
Codon, Nonsense
Dog
EC 1.-
EC 1.14.18.-
HPS3 protein, human
Heterogeneity
Intracellular Signaling Peptides and Proteins
Journal Article
Melanosome
Membrane Glycoproteins
Oxidoreductases
Pigmentation
Research Support, Non-U.S. Gov't
TYRP1 protein, human
Wgs
Whole genome sequence

Anmerkungen:

Date Completed 19.03.2021

Date Revised 19.03.2021

published: Electronic

Citation Status MEDLINE

doi:

10.3390/genes11060636

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311061753