Developmental Abnormalities in Common Laboratory Mammals

Birth defects in fetuses and neonates from common laboratory mammals, thanks to UTAH vets.

Syndromes and Combining Terms

Caudal dysplasia

Severe reduction of caudal structures, including reduction of or absence of hind limbs, tail, and/or sacral area.

Cheilognathopalatoschisis

Cleft lip, jaw, and palate; also called Cheilognathouranoschisis

Cheilognathoschisis

Cleft lip and jaw

Craniorachischisis

Failure of the neural tube to close in regions of both the brain and spinal cord.

Ethmocephaly

Some degree of cyclopia in which the eyes may be closely set but the nose is hypoplastic (rudimentary).

Otocephaly

Extreme underdevelopment of the lower jaw, permitting close approximation or union of the ears on the anterior aspect of the neck.

Rhinocephaly

Proboscis-like nose above partially of completely fused eyes.

Sirenomelia

Any of several degrees of side-to-side fusion of lower extremities and concomitant midline reduction of the pelvis. Soft tissues and long bones, lower paw (feet), and viscera of the pelvis tend to be reduced or absent; anus and external genitalia are often absent.

Tetralogy of Fallot

Defect of the heart which includes all of the following: pulmonary stenosis, interventricular septal defect, dextraposed aorta overriding the ventricular septum, and enlarged right ventricular wall.

 

This list is of descriptive terms which are used more than once in the glossary.

 

Term

Definition

Synonym or
Related Term

Non-Preferred
Term

Absent

An absolute failure of development of an organ or part; in the case of bone, no cartilage model is present

Agenesis, Aplastic

Missing

Atresia

Absence or closure of a normal body orifice or tubular organ

Imperforate

 

 

Bipartite ossification

Having two separate ossification sites

Bifid ossification

Split

Bent

Abnormal curvature of a normally straight structure

Angulated, Bowed

 

 

Branched

Deviation from the predominant pattern due to displacement and/or duplication of one or more normally occurring structures

Bifurcated, Forked

 

 

Cyst

Any abnormal sac; usually containing fluid or other material

 

 

 

 

Dilated

Widened or expanded orifice or vessel

Bulbous

Swollen

Discolored

Not the normal color

Mottled, Pale

 

 

Distended

Enlarged or expanded organ

 

 

Swollen

Diverticulum

A localized sac or pouch formed in the wall of a hollow viscus and opening into its lumen

 

 

 

 

Dumbbell ossification

Two roughly spherical ossification sites attached at or near the mid line by an ossified bridge

Dumbbell-shaped ossification

Bilobate, Bilobed

Enlarged

Larger than normal

 

 

Hyperplastic

Fistula

Abnormal passage or commun-ication between two normally unconnected structures, body cavities, or the surface of the body

 

 

 

 

Fused

Joined or blended together

 

 

 

 

Hemicentric

Absence of either hemicentrum of a centrum

 

 

 

 

Hemivertebra

Absence of a lateral half (arch + hemicentrum), or major part of a lateral half of a vertebra

 

 

 

 

Hemorrhagic

Descriptive of any tissue into which abnormal bleeding is observed (may be graded as petechia, purpura, ecchymosis, or hematoma)

 

 

 

 

Incomplete ossification

Partial ossification (as assessed by Alizarin Red uptake) at a site which, in controls of the same age, usually has a more advanced degree of ossification

Reduced ossification

Delayed ossification, Retarded ossification

Malpositioned

Not occurring in the proper position and/or orientation

Displaced, Ectopic

Misdirected, Dislocated

Misaligned

Abnormal relative position of structures on opposite sides of a dividing line or about the center or axis

 

 

Unaligned

Misshapen

Abnormally shaped [Not to be used to describe sites of incomplete ossification]

Abnormally shaped, Asymmetric, Irregularly shaped

 

 

Narrowed

Constriction of a cylindrical structure, such as the aorta or tail, or of a lumen

Coarctation, Constricted, Stenosis, Stricture

 

 

Retro-esophageal

Passing dorsal to the esophagus

 

 

 

 

Retrotracheal

Passing dorsal to the trachea

 

 

 

 

Short

Less than the normal or expected length

Rudimentary

 

 

Small

Incompletely developed structure, or less than normal in size

Aplastic, Hypoplastic, Reduced, Rudimentary

Underdeveloped

Split

Division of a single structure (usually into two parts) with no intervening structure between the parts

Bifid, Bipartite, Cleft

 

 

Supernumerary

More than the usual or expected number

Additional, Extra

Accessory

Thickened

A widening of a skeletal element relative to normal

 

 

Bulbous, Clubbed

Unossified

Absence of ossification (as assessed by Alizarin Red uptake) at a site which, in controls of the same age, is usually at least partially ossified

 

 

Nonossified