OMIA 000031-9913 : Coat colour, dilution, MLPH-related in Bos taurus

In other species: dog , domestic cat , rabbit , American mink , sheep

Possibly relevant human trait(s) and/or gene(s) (MIM number): 609227

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2015

Cross-species summary: FN acknowledges invaluable feedback from Cord Drögemüller that has led to the name of this phene being changed from "Coat colour, diluted" to "Coat colour, dilution, MLPH-related". At the same time, a new phene "Coat colour, dilution, generic" was created.

Species-specific name: Cool gray; Larson Blue

Species-specific description: In a reversal of the normal sequence of discovery, Li et al. (2016) discovered this phenotype AFTER identifying the causal mutation, by noticing that all Belgian Blue cattle with a particular mutation (MLPH: c.87_96del; p.Glu32Aspfs*1), which inactivates MLPH, have an expected dilution phenotype which the authors called "cool gray".

History: Dikmen et al. (2017) reported "a previously undescribed coat color phenotype in Holstein cattle. Larson Blue Holsteins, located on a dairy in south Florida, exhibit a coloration pattern that is similar to that of black and white or red and white Holsteins except that, instead of being black or red, darker regions of the body vary in color from gray to taupe. The Larson Blue phenotype was readily apparent in young calves."

Molecular basis: As reported by Li et al. (2016) [published online in 2015], "In the course of a reverse genetic screen in the Belgian Blue cattle breed, we uncovered a 10-bp deletion (c.87_96del) in the first coding exon of the melanophilin gene (MLPH), which introduces a premature stop codon (p.Glu32Aspfs*1) in the same exon, truncating 94% of the protein." Belgian Blue cattle homozygous for this mutant (and with the appropriate genotype at the epistatic KIT locus) all exhibited a dilution coat colour phenotype (as expected with a mutation that inactivates MLPH), which the authors called "cool gray".

Having shown that the Larson Blue "phenotype is not due to inheritance of known mutations causing coat color variation in cattle, including dominant red, Telstar, silver color dilutor, or Dun color", Dikmen et al. (2017) whole-genome sequenced two Larson Blue cows and identified "Three variants with moderate effects on the melanophilin (MLPH) gene were identified in 2 Larson blue cows" but noted that "tools for prediction of the simultaneous effect of 3 missense mutations on the MLPH protein are not available, so additional research is needed to confirm the effect of these AA changes on MLPH function. It is also not known whether the variants identified in MLPH exist in wild-type cows in the Larson herd."

Prevalence: Li et al. (2016) reported a 5% frequency of the p.Glu32Aspfs*1 allele in Belgian Blue cattle.

Breed: Belgian Blue.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
MLPH melanophilin Bos taurus 3 NC_037330.1 (116959514..117005443) MLPH Homologene, Ensembl, NCBI gene

Variants

By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
Belgian Blue Coat colour, cool gray MLPH deletion, small (<=20) c.87_96del p.Glu32Aspfs*1 2016 26582259

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2017 Dikmen, S., Dahl, G.E., Cole, J.B., Null, D.J., Hansen, P.J. :
The Larson Blue coat color phenotype in Holsteins: Characteristics and effects on body temperature regulation and production in lactating cows in a hot climate. J Anim Sci 95:1164-1169, 2017. Pubmed reference: 28380539. DOI: 10.2527/jas.2016.1148.
2016 Li, W., Sartelet, A., Tamma, N., Coppieters, W., Georges, M., Charlier, C. :
Reverse genetic screen for loss-of-function mutations uncovers a frameshifting deletion in the melanophilin gene accountable for a distinctive coat color in Belgian Blue cattle. Anim Genet 47:110-3, 2016. Pubmed reference: 26582259. DOI: 10.1111/age.12383.

Edit History


  • Created by Frank Nicholas on 13 Sep 2018
  • Changed by Frank Nicholas on 13 Sep 2018
  • Changed by Frank Nicholas on 02 Mar 2020