title: Sirenomelia: an epidemiologic study in a large dataset from the International Clearinghouse of Birth Defects Surveillance and Research, and literature review.
abstract: Sirenomelia is a very rare limb anomaly in which the normally paired lower limbs are replaced by a single midline limb. This study describes the prevalence, associated malformations, and maternal characteristics among cases with sirenomelia. Data originated from 19 birth defect surveillance system members of the International Clearinghouse for Birth Defects Surveillance and Research, and were reported according to a single pre-established protocol. Cases were clinically evaluated locally and reviewed centrally. A total of 249 cases with sirenomelia were identified among 25,290,172 births, for a prevalence of 0.98 per 100,000, with higher prevalence in the Mexican registry. An increase of sirenomelia prevalence with maternal age less than 20 years was statistically significant. The proportion of twinning was 9%, higher than the 1% expected. Sex was ambiguous in 47% of cases, and no different from expectation in the rest. The proportion of cases born alive, premature, and weighting less than 2,500 g were 47%, 71.2%, and 88.2%, respectively. Half of the cases with sirenomelia also presented with genital, large bowel, and urinary defects. About 10-15% of the cases had lower spinal column defects, single or anomalous umbilical artery, upper limb, cardiac, and central nervous system defects. There was a greater than expected association of sirenomelia with other very rare defects such as bladder exstrophy, cyclopia/holoprosencephaly, and acardia-acephalus. The application of the new biological network analysis approach, including molecular results, to these associated very rare diseases is suggested for future studies.
authors: Estudo Colaborativo Latino Americano de Malformações Congênitas at Departamento de Genética, Instituto de Biologia, Rio de Janeiro, Brazil. orioli@centroin.com.br
authors: Iêda M
authors: IM
authors: Orioli
authors: Emmanuelle
authors: E
authors: Amar
authors: Jazmin
authors: J
authors: Arteaga-Vazquez
authors: Marian K
authors: MK
authors: Bakker
authors: Sebastiano
authors: S
authors: Bianca
authors: Lorenzo D
authors: LD
authors: Botto
authors: Maurizio
authors: M
authors: Clementi
authors: Adolfo
authors: A
authors: Correa
authors: Melinda
authors: M
authors: Csaky-Szunyogh
authors: Emanuele
authors: E
authors: Leoncini
authors: Zhu
authors: Z
authors: Li
authors: Jorge S
authors: JS
authors: López-Camelo
authors: R Brian
authors: RB
authors: Lowry
authors: Lisa
authors: L
authors: Marengo
authors: María-Luisa
authors: ML
authors: Martínez-Frías
authors: Pierpaolo
authors: P
authors: Mastroiacovo
authors: Margery
authors: M
authors: Morgan
authors: Anna
authors: A
authors: Pierini
authors: Annukka
authors: A
authors: Ritvanen
authors: Gioacchino
authors: G
authors: Scarano
authors: Elena
authors: E
authors: Szabova
authors: Eduardo E
authors: EE
authors: Castilla
mesh_terms: D000328:Adult; D000569:Americas / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D035843:Biomedical Research / Q000639:trends; D002681:China / Q000453:epidemiology; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000473:pathology; D004200:Diseases in Twins / Q000453:epidemiology / Q000473:pathology; D004480:Ectromelia / Q000453:epidemiology* / Q000473:pathology; D016021:Epidemiologic Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007391:International Cooperation; D008297:Male; D008423:Maternal Age; D011159:Population Surveillance / Q000379:methods*; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D055815:Young Adult