Fear of the number 13. Written reference to this fear dates to the late 1800s. The term triskaidekaphobia appeared in the early 1900s. It is not easy to pronounce unless one speaks Greek. From treiskaideka, the Greek word for thirteen + phobia, fear of = a fear of thirteen.
Inability to open the mouth fully. This may be due to spasm of the jaw muscles and be a symptom of tetanus (lockjaw). Or it may be due to abnormally short jaw muscles, as in the trismus-pseudocamptodactyly syndrome.
The presence of three copies of a chromosome rather than the normal two. The most common trisomies in newborns are trisomy 13 (Patau syndrome), trisomy 18 (Edwards syndrome), and trisomy 21 (Down syndrome).
- Trisomy 13 syndrome
The presence of three copies of chromosome 13, rather than the normal two. Children with trisomy 13 syndrome are profoundly mentally retarded and have multiple malformations, commonly including scalp defects, hemangiomas (blood vessel malformations) of the face and nape of the neck, cleft lip and palate, malformations of the heart and abdominal organs, and flexed […]
- Trisomy 18 syndrome
The presence of three copies of chromosome 18, rather than the normal two. Children with trisomy 18 syndrome have multiple malformations and mental retardation. They characteristically have low birth weight, small head (microcephaly), small jaw (micrognathia), malformations of the heart and kidneys, clenched fists with abnormal finger positioning, and malformed feet. The mental retardation is […]
- Trisomy 21 syndrome
A common chromosome disorder, often called Down syndrome, due to an extra chromosome number 21 (trisomy 21). The chromosome abnormality affects both the physical and intellectual development of the individual. Trisomy 21 (Down) syndrome is associated with a 45% risk for heart malformations, a lesser risk of duodenal atresia (part of the small intestines is […]