Epidemiologic features and clinical subgroups of anotia/microtia in Texas

Abstract

In Texas, most anotia/microtia cases were in the unilateral and microtia groups, and 45% were isolated. Several clinical subgroups exhibited higher prevalence in males and among older mothers. Relative to whites, blacks were at lower risk and Hispanics (especially Mexico-born mothers) were at higher risk for selected types of anotia/microtia.

Prevalence at birth of congenital abnormalities of external ears in Hungary

“…The obvious predominance of unilateral cases and among them a slight right side excess in cases with isolated microtia/anotia in our study corresponded to the previous observations in other studies/countries [11,13,15,[18][19][20][21][22][23][24][25].…”

“…The mild male excess of cases with isolated ear CAs in the study was in agreement with the results of some previous studies [11,13,15,[18][19][20][21][22][23], though the cases with isolated microtia/anotia in the Italian registry did not show a male predominance [24]. The strong male excess in cases with unclassified multiple ear CA is worth mentioning, because in general previous studies did not have strict differentiation between cases with isolated and multiple ear CAs.…”

“…Among methodological differences, the classification-whether only isolated or isolated and unclassified multiple or isolated, unclassified multiple and specified CA syndromes of microtia/anotia are evaluated-and ascertainment-whether type I/minor microtia or Facio-Auriculo-Vertebral Spectrum: FAVS is included to the group of isolated microtia/anotiaproblems need to be mentioned, beyond the differences in the completeness of ascertainment and the quality of diagnoses. However, population characteristics are also important: microtia/anotia is relatively rare in white and black people, more frequent in Hispanics, mainly in children born in Mexico [15] and particularly in regions within special geographical clusters of microtia/anitia as in Quito, Ecuador [14] and the Navajo Indians in the USA state of New Mexico [16], in addition to populations living in high altitudes [17]. Nevertheless, differences in ascertainment and diagnostic criteria are probably the major source of great variations in the rate of external ear CAs, mainly microtia/anotia; therefore, their comparison demands caution among interpreting data for different populations/registries/studies.…”

Association of microtia with maternal obesity and periconceptional folic acid use

“…Maternal obesity is also a risk factor for NTDs and other birth defects, possibly due to a similar mechanism [Waller et al, 2007;Stothard et al, 2009]. Some descriptive characteristics of increased NTD risk, such as low maternal education and Hispanic ethnicity, are also seen among infants with microtia [Shaw et al, 2004;Canfield et al, 2009]. Given these epidemiologic similarities between microtia and NTDs, we explored the potential association of microtia with maternal obesity and periconceptional intake of folic-acid-containing supplements.…”

“…There is a paucity of epidemiologic information about this condition, and most previous studies have been descriptive. These studies have revealed that risk factors for microtia include advanced maternal age [Harris et al, 1996;Forrester and Merz, 2005;Canfield et al, 2009], male sex [Harris et al, 1996;Shaw et al, 2004;Canfield et al, 2009], low maternal education [Shaw et al, 2004;Husain et al, 2008;Canfield et al, 2009], and Hispanic ethnicity [Harris et al, 1996;Shaw et al, 2004;Forrester and Merz, 2005;Husain et al, 2008;Canfield et al, 2009]. Proposed etiologies include hypoxia [Castilla et al, 1999], in utero exposure to thalidomide [Buyse, 1990;Carey, 1993], maternal influenza [Lopez-Camelo and Orioli, 1996], and maternal diabetes [Mastroiacovo et al, 1995;EwartToland et al, 2000;Correa et al, 2008].…”