Patterns of co-occurring birth defects in children with anotia and microtia

Abstract

Many infants with anotia or microtia (A/M) have co-occurring birth defects, although few receive syndromic diagnoses in the perinatal period. Evaluation of co-occurring birth defects in children with A/M could identify patterns indicative of undiagnosed/unrecognized syndromes. We obtained information on co-occurring birth defects among infants with A/M for delivery years 1999-2014 from the Texas Birth Defects Registry. We calculated observed-to-expected ratios (OER) to identify birth defect combinations that occurred more often than expected by chance. We excluded children diagnosed with genetic or chromosomal syndromes from analyses. Birth defects and syndromes/associations diagnosed ≤1 year of age were considered. We identified 1310 infants with non-syndromic A/M, of whom 38% (N = 492) were diagnosed with co-occurring major defects. Top combinations included: hydrocephalus, ventricular septal defect, and spinal anomalies (OER 58.4); microphthalmia and anomalies of the aorta (OER 55.4); and cleft lip with or without cleft palate and rib or sternum anomalies (OER 32.8). Some combinations observed in our study may represent undiagnosed/atypical presentations of known A/M associations or syndromes, or novel syndromes yet to be described in the literature. Careful evaluation of infants with multiple birth defects including A/M is warranted to identify individuals with potential genetic or chromosomal syndromes.

Keywords: anotia; co-occurring defects; epidemiology; microtia.

Figure 1.. Co-occurring defects among individuals with multiple birth defect patterns involving anotia/microtia, Texas Birth Defects Registry, 1999-2014 (N=467).

Birth defects were grouped into broad categories of related defects, and information was presented for the five most commonly observed categories of co-occurring defects (heart [CHD], musculoskeletal system [MSK], central nervous system [CNS], gastrointestinal [GI] system, and orofacial clefts). Bottom left: histogram showing the number of individuals with co-occurring defects in each organ system. Bottom: legend describing evaluated birth defect combinations. Phenotypes involved are represented by black-shaded circles; combinations involving multiple co-occurring phenotypes are represented as multiple shaded circles connected by lines. Top: histogram showing the number of individuals with anotia/microtia and the index combination (e.g., among 133 individuals with anotia/microtia and heart defects, 59 were diagnosed with co-occurring CHD only, 25 with co-occurring CHD and MSK anomalies, six with co-occurring CHD and clefts, etc.).