Genetic Mutations
Patau syndrome
Patau
syndrome (trisomy 13)
Concept
Polymalformative severe congenital syndrome,
with survival rarely exceeds the year of life, caused by
the presence of three copies of chromosome 13 in the karyotype.
Etiology
Like other human trisomies, most cases of trisomy 13
to chromosomal non-disjunction
during meiosis must be primarily in the maternal gamete. In these
pregnancies and maternal age
are somewhat increased paternal average (31.3
and 33.7 years respectively).
Approximately 20% of cases are due to translocation, with
the t (13q14) the most common. Only 5% of these translocations
is inherited from one parent. The mosaics represent another
5% of cases of trisomy 13, where the malformation
condition is usually less severe.
Prenatal history
affected trisomy 13 fetuses have multiple abnormalities that can be detected prenatally by ultrasound.
These include CNS abnormalities, especially holoprosencephaly,
facial malformations, heart and kidney.
Often the intrauterine
growth retardation.
The association of these anomalies
is forced indication of fetal karyotype through
amniocentesis or chorionic
villi. About 30% of
trisomy 13 pregnancies
have polyhydramnios or oligohydramnios.
Prevalence
the prevalence of trisomy 13 is about 1/12 000
live births. The rate
of spontaneous abortions is high
and represents about 1% of spontaneous abortions recognized.
There is a slight excess of cases
of female to male.
Clinic Features
Newborns with Patau syndrome show a set of features that enable malformations clinical suspicion at the time of birth the most common clinical findings (Figure 1) are abnormalities of the midline structures, including holoprosencephaly, cleft lip with or without cleft palate and omphalocele. There are also frequent cardiac malformations, especially VSD, limb anomalies (polydactyly, club feet), kidney defects, cryptorchidism in males or the presence of single umbilical artery. Most patients with Trisomy 13 have a postnatal growth retardation.
Severe psychomotor retardation is practically constant and it is evident from the first months of life.
Less common clinical manifestations are the scalp defects, microcephaly, Dandy- Walker anomaly, enlarged cisterna magna, cyclopean, macroftalmia with ocular hypotelorism and excess skin on back of the neck due to edema or cystic hygroma antenatal.
Newborns with Patau syndrome show a set of features that enable malformations clinical suspicion at the time of birth the most common clinical findings (Figure 1) are abnormalities of the midline structures, including holoprosencephaly, cleft lip with or without cleft palate and omphalocele. There are also frequent cardiac malformations, especially VSD, limb anomalies (polydactyly, club feet), kidney defects, cryptorchidism in males or the presence of single umbilical artery. Most patients with Trisomy 13 have a postnatal growth retardation.
Severe psychomotor retardation is practically constant and it is evident from the first months of life.
Less common clinical manifestations are the scalp defects, microcephaly, Dandy- Walker anomaly, enlarged cisterna magna, cyclopean, macroftalmia with ocular hypotelorism and excess skin on back of the neck due to edema or cystic hygroma antenatal.
Treatment
Infants with trisomy 13 often require medical care from the moment of birth
because 2/3 of the cases they score below 7 in
the Apgar score in the first
minute, a figure that drops to 1/3
to 5 minutes of life. Because heart defects are
the leading cause of morbidity and mortality in trisomy 13, the ethical question of whether surgical repair is indicated given the poor
prognosis of the box both physically and
intellectually arises. About 2/3
of patients are discharged
and require specialist home care, requiring the intervention of a multidisciplinary team. Currently there percentiladas growth
charts for children with trisomy 13 to 3 years.
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