Categories: Integument (skin) phene

Links to MONDO diseases: No links.

Mendelian trait/disorder: unknown

Considered a defect: yes

Cross-species summary: Also known as Pattern Baldness

Species-specific description: Brunner et al. (2019): "Bald thigh syndrome (BTS) is a hair loss disorder seen in Greyhounds and other sighthound breeds into which the Greyhound has been introgressed such as Whippets, Galgo Español, and Magyar Agár."

Inheritance: Brunner et al. (2019) concluded "that BTS [bald thigh syndrome] is caused by structural HS [hair shaft] defects which are associated with the downregulation of genes and proteins essential for HS differentiation and HS assembly. The underlying genetic defect has not yet been identified and we suggest a complex mode of inheritance."

Molecular basis: Brunner et al. (2019): "The genetic analysis revealed a missense variant in the IGFBP5 gene homozygous in all available Greyhounds and other sighthounds. Further research is required to clarify whether the IGFBP5 variant represents a predisposing genetic risk factor." Because of this cautious conclusion, this variant has not been included in the OMIA table of likely causal variants.

Genetic engineering: Unknown
Have human generated variants been created, e.g. through genetic engineering and gene editing

Clinical features: Brunner et al. (2019): "BTS is characterized by bilateral hair loss on the caudal and lateral thighs, but alopecia may extend to the distal hind legs, the ventral abdomen and the chest. In some cases even the ventral neck is involved. Dogs of any age and sex may be affected."

Pathology: Brunner et al. (2019): "While the histology is rather unspecific in most cases, trichogram analysis and scanning electron microscopy revealed severe structural abnormalities in hair shafts of affected dogs. This finding is supported by the results of the transcriptomic and proteomic profiling where genes and proteins important for differentiation of the inner root sheath and the assembly of a proper hair shaft were downregulated."

Breeds: Galgo Español (Dog) (VBO_0200557), Greyhound (Dog) (VBO_0200638), Magyar Agár (Dog) (VBO_0200842), Whippet (Dog) (VBO_0201421).
Breeds in which the phene has been documented. For breeds in which a likely causal variant has been documented, see the variant table below