Categories: Skeleton phene (incl. short stature & teeth)

Single-gene trait/disorder: yes

Mode of inheritance: Autosomal recessive lethal

Disease-related: yes

Key variant known: no

Species-specific symbol: Initially ac; later (Robinson, 1958) ac-1

History: This mutant phenotype was first reported by Brown and Pearce in three papers in 1945.

Clinical features: As first reported by Brown and Pearce (1945), this form of achondroplasia "is present at birth and is characterized by size reduction, by a disproportion of bodily parts, most marked in the extremities, and by an invariably lethal effect. The animals are still-born or die very shortly after birth. In physical appearance and in the character of the skeletal changes as shown by x-ray photographs, achondroplasia in the rabbit has a remarkable resemblance to the disease in man and in cattle and dogs." As summarised by Robinson (1958; pp 340-341), "They are diminutive with clearly noticeably abbreviated limbs. The tail is short and fleshy while the nose appears flattened. The head is squarish with a depression across the base of the nose. The tongue is large and usually protrudes from between the teeth. Folding of the ears towards the face is not uncommonly found and a cleft palate may be present. The body appears relatively . large with a swollen and bulging abdomen. The skin is loose and occurs in folds around the regions of the shoulders and rump; while being tightly stretched across the distended belly. No cases of nakedness were observed although the fur appeared subnormally developed. Some deficiency of pigmentation was noted, the skin appearing greyish. A surprising feature was the absence of the usual signs of rigour mortis, contrasting with that of normal young discovered dead."