When the damage of epiphyseal
cartilage of femur of child or animal due to chronic osteomyelitis, the bone
grows no more and the organism has a shortened and deformed leg. It is known as
malformation.
Developmental anomalies and
malformations include-
Ø
Failure of a structure to disappear, e.g.,
–
Persistence of
ductus arteriosus,
–
Persistent
foramen ovale,
–
Interventricular
septal defect,
–
Atresia ani.
–
Aberrant
structures, e.g.,
–
Pancreatic tissue
in the wall of stomach,
–
Adrenal tissue in
kidney or testis,
–
Dermoid cyst in
the skin,
–
Dentigenous cysts
in head and neck,
–
Ectopia cordis.
–
Duplications, e.g.,
–
Partial
duplication of head (diprosopia),
–
Twin kitten
joined at abdomen where one is only partially developed (heteradelphia),
–
Twin pigs joined
at the thorax (thoracopagus).
Causes
Ø
Viral infections, e.g., BVD causes cerebellar
hypoplasia in calf,
Ø
Intrauterine exposure to poisons ingested by
mother, e.g.,
–
Veratrum
californicum causes absence of palate.
–
Thalidomide
causes no development of leg
Ø
Vitamin deficiency, e.g.,
–
Vit. A deficiency
causes microphthalmia, corneal dermoid,
–
Folic acid
deficiency causes leukopenia, macrocytic anemia
Ø
Genetic factors-
genetic mutations may cause abnormal growth of any organ.
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