Microtia-anotia

Description

Microtia-anotia (M-A) can occur either as an isolated defect or in association with other defects. Only in a minority of cases has a genetic or environmental cause been found; in these cases, M-A is usually part of a specific pattern of multiple congenital anomalies. For instance, M-A is an essential component of isotretinoin embryopathy (OMIM ), is an important manifestation of thalidomide embryopathy, and can be part of the prenatal alcohol syndrome and maternal diabetes embryopathy. M-A occurs with a number of single gene disorders, such as Treacher Collins syndrome (OMIM ), branchiotorenal/branchiootic syndromes (see {113650} and {602588}), oculoauricular syndrome (OMIM ), microtia with hearing impairment and cleft palate (OMIM ), or chromosomal syndromes, such as trisomy 18. M-A also occurs as part of seemingly nonrandom patterns of multiple defects, such as Goldenhar syndrome (OMIM ) (Mastroiacovo et al., 1995).Alasti and Van Camp (2009) reviewed the genetics of microtia and microtia-associated syndromes and discussed their clinical aspects in relation to the causative genes. They stated that the estimated prevalence of microtia is 0.8 to 4.2 per 10,000 births, that it is more common in males, and that it can have a genetic or environmental predisposition.

Clinical Features

• Microtia
• Small for gestational age
• Holoprosencephaly
• Anotia