Variable expressivity in Patau syndrome is not all related to trisomy 13 mosaicism

Abstract

Patau syndrome (trisomy 13) is very rare in live-born babies. Individuals with this chromosomal syndrome have a short lifespan and are rarely seen beyond infancy. This study is aimed at the clinical spectrum, natural history, and survival of patients with trisomy 13. We reviewed the detailed data of 13 Patau syndrome live-born babies. Among them two individuals were delivered from continuation of pregnancy even after prenatal diagnosis. The remaining 11 patients were born to younger mothers who did not undergo amniocentesis because no major anomalies except for cleft lip/palate were found on prenatal sonograms. The common features of Patau syndrome including the clinical triad (microphthalmia, cleft lip/palate, and polydactyly) and non-cyanotic heart defects were always found in our series. However, certain serious central defects (holoprosencephaly, omphalocele, and single umbilical artery), which are easily recognized from prenatal sonogram, occurred less frequently than those stated in the literature. The median survival time was 95 days and was longer than that previously reported. There were two infants with trisomic mosaicism with different outcomes in both clinical spectrum and survival. Otherwise, we also found the increased recurrence risks of aneuploidy in two individuals, and the longest survivor (84 months) of non-mosaic trisomy 13 in Taiwan. We thus suggest that long-term survival in our series is strongly correlated with different expressivity after prenatal selection, in addition to cytogenetic mosaicism. Less associated anomalies such as polyhydramnios, oligohydramnios, intrauterine growth retardation, single umbilical artery, eye defects, holoprosencephaly, omphalocele, and polycystic kidney may contribute to their clinical courses.

Nine children over the age of one year with full trisomy 13: A case series describing medical conditions

“…Hsu and Hou [2007] reported all infants with rocker bottom feet (n ¼ 13) and over 75% had cleft lip and/or palate. In Peroos et al [2012] case study of an 8-year-old female with trisomy 13, polydactyly, low-set ears and cleft palate were noted.…”

“…They also offer a view of changes over time in relation to care such as the provision of cardiac surgery. Case study and series studies further articulate common medical needs and their resolution along with, largely, highlight positive outcomes [e.g., Baty et al, 1994;Hsu & Hou, 2007]. Long-term survival is possible when neonates gestate for over 37 weeks, present without key medical conditions, such as holoprosencephaly, and are accorded necessary interventions perinatally and through the early childhood years.…”

“…[Lin et al, 2007;Petry et al, 2013]. Many infants also present with cardiac anomalies including patent ductus arteriosus (PDA) or ventricular septal defect (VSD), respiratory difficulties including central apnea and upper airway problems and feeding difficulties [Rios et al, 2004;Pont et al, 2006;Hsu and Hou, 2007;Jones et al, 2013]. In addition, Lakovschek et al [2011] and Morris and Savva [2008] discuss the high incidence of fetal loss after prenatal diagnosis of trisomy 13.…”

“…Graham et al [2004] also report on successful cardiac surgery in their sample, which included 11 children with trisomy 13. Additional reports of better outcome are available [Hsu and Hou, 2007;Kaneko et al, 2008;Maeda et al, 2011]. There are also recent United States data that point to the increased delivery of surgical interventions and other hospital-based care for infants, toddlers, and older children with trisomy 13 [Nelson et al, 2012].…”

Epileptic spasms and early-onset photosensitive epilepsy in Patau syndrome: An EEG study

“…With an incidence between 1/5000 and 1/20,000 births [1], Patau syndrome is the 3rd most common autosomal trisomy, clinically defined on the basis of a triad of signs: microphthalmia/anophthalmia, cleft lip and palate and postaxial polydactyly [2].…”