Patau Syndrome

 Patau Syndrome : 

Patau syndrome, also called trisomy 13, is a clinical syndrome that occurs when all or some cells of the body contain an extra copy of chromosome 13.  It is characterized by cleft lip, cleft palate, cerebral defects, anophthalmia, simian creases, polydactyly, trigger thumbs, and capillary hemangiomata. This activity describes the evaluation and management of Patau syndrome and reviews the role of the interprofessional team in improving care for patients with this condition.

Objectives:

.Summarize the epidemiology of Patau syndrome.

.Describe the use of chorionic villus sampling, amniocentesis and DNA analysis in the prenatal evaluation of Patau syndrome.

.Review the treatment considerations for patients with Patau syndrome.

.Outline the importance of improving care coordination among the interprofessional team to enhance the delivery care by counseling the family on the poor prognosis of Patau syndrome so they can make informed decisions about its management.

Fig: A 40-year-old woman gave birth to a girl at 39 weeks gestation. She had been lost to follow-up after her first prenatal appointment, and reports that she felt well during the pregnancy. The neonate born has significant cleft lip and cleft palate and microcephaly. An ultrasound shows ventricular septal defect of the heart as well as cerebral malformations. The neonate passes away a few hours later. The pediatrician informs the family that this child likely had an autosomal trisomy disorder.

Signs and Symptoms:

Of those fetuses that do survive to gestation and birth, common abnormalities may include:

.Nervous system

  .Intellectual disability and motor disorder

  .Microcephaly

  .Holoprosencephaly (failure of the forebrain to divide       properly) and associated facial deformities such as cyclopia

  .Structural eye defects, including microphthalmia, Peter's     anomaly, cataract, iris or fundus (colombia), retinal dysplasia   or retinal detachment, sensory nystagmus, cortical visual   loss,  and optic nerve hypoplasia

  .Meningomyelocele (a spinal defect)

.Musculoskeletal and cutaneous

  .Polydactyly (extra digits)

  .Proboscis

  .Congenital trigger digits

  .Low-set ears

  .Prominent heel

  .Deformed feet known as rocker-bottom feet

  .Omphalocele (abdominal defect)

  .Abnormal palm pattern

  .Overlapping of fingers over thumb

  .Cutis aplasia (missing portion of the skin/hair)

  .Cleft palate

.Urogenital

  .Abnormal genitalia

  .Kidney defects

.Other

  .Heart defects (ventricular septal defect)(Patent Ductus   Arteriosus)

  .Dextrocardia

  .Single umbilical artery

Pathophysiology:

An extra copy of chromosome 13 causes the defects in Patau syndrome. Advanced maternal age is a risk factor for this pathology because of the increased frequency of nondisjunction in meiosis. This extra copy of chromosome 13 disrupts normal embryonic development and leads to multiple defects.

Evaluation and Diagnosis:

Diagnosis of Patau syndrome can be made prenatally with chorionic villi sampling, amniocentesis, or fetal free DNA analysis. These methods of testing detect trisomy 13. Prenatal ultrasound can also help detect the malformations of Patau syndrome, such as holoprosencephaly or other central nervous system anomalies, facial anomalies, skeletal abnormalities, renal or cardiac defects, and growth restriction that are typically present. Prenatal ultrasound after 17 weeks gestation is most sensitive in detecting the abnormalities of Patau syndrome. Abnormal findings should have confirmation performed with a cytogenetic evaluation of fetal cells.

Tissue microarray has increased the ability to diagnose genetic alterations in fetal death, especially when the fetus is macerated.

Treatment :

Intensive treatment of Patau syndrome is controversial due to the universally poor prognosis of patients despite treatment.

At delivery, infants diagnosed with Patau syndrome may need post-delivery oxygenation and ventilation; this may require intubation or tracheostomy due to facial defects. Patients with cardiac defects may require cardiac surgery to repair common cardiac abnormalities. Other surgeries may be indicated for common defects including herniorrhaphy, cleft lip repair, feeding tube placement, or corrective orthopedic surgeries.

Additional treatments may be performed including specialized dietary feeds, seizure prophylaxis, prophylactic antibiotics for urinary tract infections, and the use of hearing aids.

Despite aggressive management, median survival only extends to 733 days in the most recent cohorts of patients.