Acromelia - shortening of the terminal parts of the limbs (hands and feet) in relation to the upper and middle limb segments.
Atlantoaxial Instability - abnormal extra motion occurring between the first and second cervical vertebrae (C1 and C2). This extra motion places the spinal cord at risk as it travels between C1 and C2. Typically this results from either an abnormal odontoid process or ligamentous laxity.
Amniocentesis - a procedure typically done with ultrasound guidance in which a needle is passed through the abdominal wall and the uterus and into the fluid which surrounds a baby. Some of the amniotic fluid is then removed thru the needle and this fluid can be used for various types of genetic testing. This is typically done at 16-18 weeks gestation.
Anterior - relating to the front of the body.
Autosomal Dominant - when a condition is caused by having only a single mutant copy of a particular gene and that gene is located on one of the 22 pairs of autosomal chromosomes.
Autosomal Recessive - when a condition is caused by having two mutant copies of a particular gene and that gene is located on one of the 22 pairs of autosomal chromosomes.