Skeletal limb abnormalities refer to a variety of bone structure problems in the arms or legs (limbs).

Skeletal limb abnormalities are most often used to describe defects associated with your genes, chromosomes, or that occur during pregnancy. They may be due to problems experienced by a fetus before birth. For example, exposure to drugs and medications, infections, positioning, or injury.

The abnormalities are often present at birth.

Limb abnormalities can develop after birth in persons who have rickets and other diseases that affect bone structure.

Skeletal limb abnormalities may be due to:

• Metabolic diseases
• Malnutrition
• Genetic diseases and chromosomal abnormalities, including Marfan syndrome, Down syndrome, Apert syndrome, Basal cell nevus syndrome, and other conditions
• Pregnancy problems, including limb amputation from amniotic band (disruption sequence)
• Drugs the mother took while pregnant -- for example, thalidomide causes the upper part of the arms or legs to be missing; aminopterin causes shortness of the forearm
• Injury during birth
• Cancer

Call your health care provider if you have any concerns about limb length or appearance.

An infant with limb abnormalities generally has other symptoms and signs that, when taken together, define a specific syndrome or condition or give a clue as to the cause of the abnormality. Diagnosis of that condition is based on a family history, medical history, and thorough physical evaluation.

Medical history questions may include:

• Does anyone in your family have skeletal abnormalities?
• Were there any problems during pregnancy?
• What drugs or medications were taken during the pregnancy?
• What other symptoms or abnormalities are present?

Laboratory studies such as chromosome studies, enzyme assays, x-rays, and metabolic studies may be done to confirm a suspected disorder.

Knobloch J, Shaughnessy Jr JD, Ruther U. Thalidomide induces limb deformities by perturbing the Bmp/Dkk1/Wnt signaling pathway. FASEB J. 2007 Feb 5; [Epub ahead of print].

Canale ST. Campbell's Operative Orthopaedics. 10th ed. St. Louis, Mo: Mosby; 2003:1043.