In other species: chicken , dog , American black bear , domestic cat , pig , taurine cattle , goat , golden hamster , bongo , water buffalo

Categories: Endocrine / exocrine gland phene (incl mammary gland)

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 274700 (trait) , 188450 (gene)

Links to relevant human diseases in MONDO:

• MONDO:0010135: thyroid dyshormonogenesis 3

Mendelian trait/disorder: yes

Disease-related: yes

Key variant known: no

Cross-species summary: Goitre is the enlargement of the thyroid gland, causing a swelling in the front of the neck. The condition can develop due to nutritional iodine deficiencies but familial forms of this disorder have been identified in several species. The molecular basis been determined for familial goitre in cattle and goats. Also spelt goiter.

Species-specific description: Mayo and Mulhearn (1969) provided extensive evidence supporting autosomal recessive inheritance of this disorder in South Australian merinos. Normal thyroglobulin is absent from affected sheep, but seems to be replaced by thyroglobulin-like, albumin-like and immunoglobulin-like iodoproteins, with the latter two most probably arising from outside the thyroid gland (Dolling and Good, 1976).

Clinical features: The following details are taken from Mayo and Mulhearn (1969). Both lobes of the thyroid gland are enlarged and ovoid, usually in the range 1" to 3" (2.5 cm to 7.6cm) along their longest axes.. Other abnormalities often occur: the area surrounding the nostrils is flattened dorso-ventrally, and the transverse folds of skin ("nose wrinkle") over the nasal bones and immediately behind the nostrils are very pronounced and harsh; ears are oedematous and tend to flop, thereby giving greater prominence to the poll; carpal joints are swollen, and legs, particularly the forelegs, are bowed either inwards or outwards, resulting in oblique plantar surfaces of the hooves; some animals are low at the withers Affected lambs are generally very weak, and are often highly sensitive to the effects of harsher environmenents. Mortality is very high in the first year of life. Wool seems to be normal, except for birthcoats, which tend to be "silky" (lustrous). On post-mortem, the weight of thyroid gland varies from greater than 5 g up to 222 g, compared with a maximum of less than 5 g in normal sheep.