Amelia

Amelia

Amelia is a rare congenital disorder characterized by the complete absence of one or more limbs at birth. It is a type of limb reduction defect and can affect the arms, legs, or both. The condition can occur as an isolated defect or as part of a syndrome with other anomalies.

Etiology

The exact cause of amelia is not well understood, but it is believed to result from disruptions during the early stages of limb development in the embryo. Potential causes include genetic mutations, environmental factors, or a combination of both. Some cases have been linked to teratogenic agents, such as the drug thalidomide, which was used in the late 1950s and early 1960s and caused a significant number of limb defects in newborns.

Epidemiology

Amelia is an extremely rare condition, with an estimated incidence of 1 in 50,000 to 1 in 200,000 live births. The incidence may vary by geographic region and population. There is no known predilection for any particular sex or ethnic group.

Clinical Presentation

The primary feature of amelia is the absence of one or more limbs. The condition can be classified based on the number and location of the missing limbs:

• Monomelia: Absence of one limb.
• Bimelia: Absence of two limbs.
• Trimelia: Absence of three limbs.
• Tetramelia: Absence of all four limbs.

In some cases, amelia may be associated with other congenital anomalies, such as cleft lip and palate, congenital heart defects, or spina bifida.

Diagnosis

Amelia is typically diagnosed at birth through physical examination. Prenatal diagnosis is possible through ultrasound imaging, which can detect limb absence as early as the first trimester. Genetic testing may be conducted to identify any underlying genetic causes or syndromes associated with the condition.

Management

Management of amelia involves a multidisciplinary approach, including:

• Prosthetic Fitting: Early fitting of prosthetic limbs can help improve mobility and function.
• Physical Therapy: To enhance motor skills and adapt to prosthetic use.
• Occupational Therapy: To assist with daily living activities and promote independence.
• Psychological Support: For the patient and family to cope with the emotional and social challenges of the condition.

Prognosis

The prognosis for individuals with amelia depends on the presence of associated anomalies and the level of functional adaptation achieved. With appropriate interventions, many individuals can lead fulfilling lives.

See Also

• Limb reduction defect
• Phocomelia
• Congenital disorder

References

• Jones, K. L. (2013). Smith's Recognizable Patterns of Human Malformation. Elsevier.
• Moore, K. L., Persaud, T. V. N., & Torchia, M. G. (2015). The Developing Human: Clinically Oriented Embryology. Elsevier.

External Links

• National Organization for Rare Disorders - Amelia