Syndromes: Trisomy 13 (Patau syndrome)

A series about conditions with common symptoms that constitute syndromes

A series about conditions with common symptoms that constitute syndromes

Picture: Science Photo Library

Trisomy 13 is also referred to as Patau syndrome after Klaus Patau, a cytogeneticist at the University of Wisconsin. In 1960, with his associates, Patau first recognised that this autosomal chromosomal condition resulted from having three copies of chromosome 13 instead of two copies (Patau et al 1961).

It is the third most common trisomy in live births (Hall et al 2007, Vendola et al 2010, Houlihan and O’Donoghue 2013) due to non-disjunction in the first meiotic division (Hall et al 2007) and can be full or partial trisomy (Robertsonian translocation) or mosaicism (Wu et al 2013). More than 91% of cases are maternal in origin with maternal age being identified as a risk factor for the syndrome (Staso et al 2018).

Most infants born alive with this syndrome die within the first days or weeks of life due to medical complications associated with poor development of the central nervous system (CNS), central apnoea resulting from major cerebral malformations (Matthews 1999, Rios et al 2004) and multi-organ system failure (Hall et al 2007, Vendola et al 2010, Wu et al 2013). Wu et al’s (2013) study on survival of live births with trisomy 13 in England and Wales between 2004-2011 found differences in the survival rates of babies.

In total 8% of babies with full trisomy, 29% with partial trisomy and 80% with mosaicism survived at least the first year of the lives – with girls living longer than boys.

Prenatally ultrasound and invasive diagnostic testing (chorionic villi sampling, amniocentesis) can be used to detect trisomy 13 (Barry et al 2015, Staso et al 2018,) with the majority of cases being detected at the second trimester anomaly scanning (Parker et al 2003, Barry et al 2014). Postnatally the diagnosis is confirmed by chromosomal analysis (Rios et al 2004).

The birth prevalence rate is between one in 5,886 and one in 9,522 (Parker et al 2003).

The most common abnormalities associated with trisomy 13 include:

  • Eye defects including microphthalmia (small eyes), anophthalmia (congenital absence of eyes), cyclops (single orbit), synophthalmia (two orbits fused together) or ocular hypotelorism (abnormal decrease in the distance between the two eyes).
  • Cleft lip and palate, nasal malformations, low set ears with an abnormal helix.
  • Localised scalp defects for example, cutis aplasia.
  • Postaxial polydactyly of the feet or hands or both (extra digit at the little toe or finger).
  • Congenital cardiac defects; for example ventricular septal defect, atrial septal defect, patent ductus arteriosis.
  • Renal abnormalities; for example hydronephrosis, polycystic kidneys.
  • Genetalia abnormalities; for example in the male infant abnormal scrotum and cryptorchidism and bicornuate uterus in the female infant.
  • Omphalocele (intestines or other abdominal organs are outside the body).
  • Hypotonia.
  • Respiratory difficulties.
  • Feeding difficulties.
  • Severe to profound intellectual disability (Matthews 1999, Rios et al 2004, Bruns 2011).

Case study

Baby Eva was diagnosed with trisomy 13 at the 20-week fetal anomaly scan. The scan indicated small for gestational date, holoprosencephaly, cleft lip and palate, polydactyly, ventricular septal defect, polycystic kidney, and ocular hypotelorism. Following her diagnosis her parents met with clinicians. After counselling they decided to continue with the pregnancy.

In collaboration with the hospital staff they developed a care plan for Eva’s arrival and they made contact with SOFT, the Support Organisation for trisomy 18/13, to find out about trisomy 13 from other parents’ experiences. Eva was born alive via vaginal delivery at 38 weeks' gestation.

Her parents wanted keepsakes of Eva and so had arranged for a photographer to take photographs of her, and with the help of the midwife they took Eva’s hand and foot impressions with a clay imprint kit. Eva’s parents wanted to spend undisturbed time with her and a room was made available for them in response to their request.

Eva was in her mother’s arms when she had an apnoea attack and quietly took her last breath, she was four hours old.



  • Barry S, Walsh C, Burke A et al (2015) Natural history of fetal trisomy 13 after prenatal diagnosis. American Journal of Medical Genetics Part A. 167, 1, 147-150.
  • Bruns D (2011) Birth history, physical characteristics, and medical conditions in long-term survivors with full trisomy 13. American Journal of Medical Genetics Part A. 155 (11), 2634-2640  
  • Hall H, Chan E, Collins A et al (2007) The origin of trisomy 13. American Journal of Medical Genetics Part A. 143A, 19, 2242-2248.
  • Houlihan O, O’Donoghue K (2013) The natural history of pregnancies with a diagnosis of trisomy 18 or trisomy 13; a retrospective case series. BMC Pregnancy and Childbirth. Springer Nature. 13, 1, 209-209.
  • Matthews A (1999) Chromosomal abnormalities: trisomy 18, trisomy 13, deletions, and microdeletions. Journal of Perinatal & Neonatal Nursing. 13, 2, 59-75.
  • Parker M, Budd J, Draper E et al (2003) Trisomy 13 and trisomy 18 in a defined population: epidemiological, genetic and prenatal observations. Prenatal Diagnosis. 23, 10, 856-860.
  • Patau K, Therman E, Smith D et al (1961) Two new cases of D1 trisomy in man. Journal of Pediatrics. 47, 2, 239-242.
  • Rios A, Furdon S, Adams D et al (2004) Recognising the clinical features of trisomy 13 syndrome. Advances in Neonatal Care. 4, 6, 332-343.
  • Staso P, Paitl S, Patel D (2018) An 8-week-old infant with trisomy 13: dilemmas for medical decision making. AME case reports. 2, 3.
  • Vendola C, Canfield M, Daiger S et al (2010) Survival of Texas infants born with trisomies 21, 18, and 13. American Journal of Medical Genetics Part A. 152A, 2, 360-366.
  • Wu J, Springett A, Morris J (2013) Survival of trisomy 18 (Edwards syndrome) and trisomy 13 (Patau Syndrome) in England and Wales: 2004–2011. American Journal of Medical Genetics Part A. 161, 10, 2512-2518.

About the authors

Sandra Fleming is assistant professor, school of nursing and midwifery, Trinity College Dublin, the University of Dublin; and Carmel Doyle is assistant professor, school of nursing and midwifery, Trinity College Dublin, the University of Dublin.

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