Table 1 Summary of known causal variants of EDA causing hypohidrotic ectodermal dysplasia (HED) in cattle (based on OMIA 000543–9913), with summary of breed and phenotype

HED1

160 kb deletion

g.unknown precise breakpoints

c.397_502del

p.Met133ValfsTer111

Hypotrichosis and oligodontia, but phenotype not described in detail and no histology presented

Holstein

[2]

HED2

Splice site variant

g.80411671A > C

c.924+2T > G

p.unknown effect on transcription

Hypotrichosis and oligodontia (absence of incisors: presence of only one molar on each side of the upper jaw). Report noted generalized hypotrichosis, thin dermis with sparse, atrophic hair follicles and reduced density of sweat glands, dry muzzle, and absence of eccrine nasolabial, tracheal, and bronchial glands

Holstein

[18]

HED3

Nonsense (stop-gain)

g.80415626G > A

c.730C > T

p.Arg244*

Hypotrichosis and oligondontia (absence of incisors, presence of only 4 maxillary premolars, and a single mandibular premolar, for a total of 5 teeth). Skin histology: On histopathologic examination, very few normal anagen hair follicles were present and in the small, scattered foci of all biopsies, there was total underdevelopment of hair follicles. Hypoplastic follicles were common, contained smaller than normal hair shafts and fewer than normal adnexal glands (both sebaceous and epitrichial)

Red Angus-Charolais-Simmental cross

[16]

HED4

19 bp deletion

g.80803015_80803033del

c.48_66del

p.Ala16Ser22fsTer55

Hypotrichosis and oligodontia (absence of incisors: presence of only one molar on each side of the upper jaw). Skin histology: The hair follicles and adnexal glands of the affected animal were smaller than normal

Holstein

[25]

HED5

Splice site variant

g.80411795C > A

c.802C > A

p.unknown effect on transcription

Hypotrichosis and complete hypodontia. Skin histology not reported

Holstein Friesian

[27]

HED6

161 bp insertion

Not reported

Hypotrichosis and oligodontia (absence of incisors and only two erupted premolar teeth). Skin: hypotrichosis or hairlessness due to a reduction in hair follicle complexes, mild superficial perivascular dermatitis involving the superficial and middle vascular plexuses and characterized by mixed mononuclear and polymorphonuclear cellular infiltrates, mild irregular epidermal hyperplasia and dilation of some lymph vessels was also found. The sweat glands were dilated with a flattened, inactive luminal epithelium. The muzzle was without nasolabial glands. Glandular structures were not observed in the trachea and bronchi

Holstein

[21]

HED7

4 bp insertion

g.80802800_80802801insCCCT

c.280_281insAGGG

p.Gly94GlnfsTer49

Hypotrichosis and hypodontia. This is a brief report, and the description of the phenotype is restricted to reference to hairlessness on most of the body, except for the distal parts of the extremities, with severe hypothermia and skin abrasions over the carpal and tarsal joints

Japanese Black

[26]

HED8

3.76 Mb inversion

g.7174882_80737442inv

p.unknown effect on transcription

Hypotrichosis and oligodontia (absence of incisors, one malformed premolar on each side of the upper jaw). Reduced size of sweat glands, sebaceous glands, and hair follicles in the affected animals. Increased density but reduced size of sebaceous glands and pilary canals

Holstein

[20]

HED9

53 kb deletion

g.80382423_80435202del

p.unknown effect on transcription

Hypotrichosis, anodontia/oligodontia, and absent or defective ectodermally derived glands. Histologically, mostly small calibre, hair follicles and larger follicles with medullated hairs were only present on the chin, tail, eyelids, tragus and distal limbs

Red Angus × Simmental

[22]

HED10

22 kb deletion

g.80516615_80538514del

c.397_502del

p.Met133ValfsTer111

British blue × Holstein–Friesian

This study