Outline of the Genetic Abnormality
Patau Syndrome is a trisomy disorder caused by the complete or partial duplication of the 13th chromosome. This website strives to deliver the most up to date research regarding what Patau Syndrome is, how it occurs, how it is diagnosed, and the implications that it has for both the parents and the child. |
OVERVIEW OF PATAU SYNDROME
Patau Syndrome, also know as Trisomy 13, occurs due to the complete or partial duplication of the 13th chromosome. This duplication is most often (90% of the time) caused by non-disjunction in maternal meiosis[1] and results in severe bodily deformations and mental retardation.[2]
A chromosome refers to the structure shown in Figure 1.1[3], which is made up of a replicated and un-replicated chromatid.
Humans have 46 chromosomes in every cell in their body, except for the haploid gamete cells (egg and sperm). Each of these chromosomes are part of a homologous pair as they carry a variation of the same DNA code as another chromosome. Thus often the human cells are referred to as having 23 pairs of chromosomes. We get these homologous pairs from our parents, one chromosome comes from our mother (maternal), and one comes from our father (paternal).In the case of Patau Syndrome the child has 47 chromosomes as shown in Figure 1.2.[4]
Patau Syndrome, also know as Trisomy 13, occurs due to the complete or partial duplication of the 13th chromosome. This duplication is most often (90% of the time) caused by non-disjunction in maternal meiosis[1] and results in severe bodily deformations and mental retardation.[2]
A chromosome refers to the structure shown in Figure 1.1[3], which is made up of a replicated and un-replicated chromatid.
Humans have 46 chromosomes in every cell in their body, except for the haploid gamete cells (egg and sperm). Each of these chromosomes are part of a homologous pair as they carry a variation of the same DNA code as another chromosome. Thus often the human cells are referred to as having 23 pairs of chromosomes. We get these homologous pairs from our parents, one chromosome comes from our mother (maternal), and one comes from our father (paternal).In the case of Patau Syndrome the child has 47 chromosomes as shown in Figure 1.2.[4]
Trisomy 13 can also be referred to as a type of aneuploidy. Aneuploidy refers to "the characteristic of having a chromosome complement that is not an exact multiple of the haploid number, with either fewer or more than the normal number of chromosome in the cell."[5]
Essentially trisomy 13 is a form of aneuploidy in which the number of chromosomes is not an exact double of the haploid number (23). Rather the karyotype of trisomy 13 shows an additional chromosome, that of chromosome 13.
PREVALENCE OF PATAU SYNDROME
Patau Syndrome is the third most prevalent chromosomal trisomy to appear in lives births, behind Trisomy 21 (Down Syndrome) and Trisomy 18 (Edwards Syndrome). Occurrence in live births is most often recorded as 1 in 9,500,[1] however some estimate the figure to range from 1 in 5,000 to 1 in 25,000.[6]
However a study conducted regarding the mortality rate of those born with Trisomy 13 found that 91% of the 70 recorded infants died within their first year of life, with the median survival rate at 7 days (this result was not distinguishable by race).[7]
REFERENCE LIST:
[1] National Genetics and Genomics Education Centre, (2013). Patau syndrome. [online] Available at: http://www.geneticseducation.nhs.uk/genetic-conditions-54/691-patau-syndrome-new [Accessed 8 Aug. 2014].
[2] Best, R. and Gregg, A. (2014). Patau Syndrome. [online] Medscape. Available at: http://emedicine.medscape.com/article/947706-overview [Accessed 9 Aug. 2014].
[3] Pass My Exames, (2012). What are chromosomes?. [online] Available at: http://www.passmyexams.co.uk/GCSE/biology/what-are-chromosomes.html [Accessed 9 Aug. 2014].
[4] Celestineteocsijournal.blogspot.com.au, (2012). 12th lesson CSI - Identity 2 - Karyotype. [online] Available at: http://celestineteocsijournal.blogspot.com.au/2012/08/csi-identity-2-karyotype.html [Accessed 9 Aug. 2014].
[5] Biology Online, (2005). Aneuploid. [online] Available at: http://www.biology-online.org/dictionary/Aneuploid [Accessed 9 Aug. 2014].
[6] Wright, M. and Tidy, C. (2013). Patau's Syndrome (Trisomy 13). [online] Patient.co.uk. Available at: http://www.patient.co.uk/doctor/pataus-syndrome-trisomy-13 [Accessed 9 Aug. 2014].
[7] Rasmussen, S., Wong, L., Yang, Q., May, K. and Friedman, J. (2003). Population-based analyses of mortality in trisomy 13 and trisomy 18. Pediatrics, 111(4), pp.777--784.
[1] National Genetics and Genomics Education Centre, (2013). Patau syndrome. [online] Available at: http://www.geneticseducation.nhs.uk/genetic-conditions-54/691-patau-syndrome-new [Accessed 8 Aug. 2014].
[2] Best, R. and Gregg, A. (2014). Patau Syndrome. [online] Medscape. Available at: http://emedicine.medscape.com/article/947706-overview [Accessed 9 Aug. 2014].
[3] Pass My Exames, (2012). What are chromosomes?. [online] Available at: http://www.passmyexams.co.uk/GCSE/biology/what-are-chromosomes.html [Accessed 9 Aug. 2014].
[4] Celestineteocsijournal.blogspot.com.au, (2012). 12th lesson CSI - Identity 2 - Karyotype. [online] Available at: http://celestineteocsijournal.blogspot.com.au/2012/08/csi-identity-2-karyotype.html [Accessed 9 Aug. 2014].
[5] Biology Online, (2005). Aneuploid. [online] Available at: http://www.biology-online.org/dictionary/Aneuploid [Accessed 9 Aug. 2014].
[6] Wright, M. and Tidy, C. (2013). Patau's Syndrome (Trisomy 13). [online] Patient.co.uk. Available at: http://www.patient.co.uk/doctor/pataus-syndrome-trisomy-13 [Accessed 9 Aug. 2014].
[7] Rasmussen, S., Wong, L., Yang, Q., May, K. and Friedman, J. (2003). Population-based analyses of mortality in trisomy 13 and trisomy 18. Pediatrics, 111(4), pp.777--784.