Chromosome 16- trisomy 16q


A rare chromosomal disorder involving an extra copy of genetic material from the long arm of chromosome 16. The type and severity of symptoms are determined by the amount and location of the duplicated genetic material. Severe cases often result in spontaneous abortion or infant death.


* Low birth weight * Severe physical retardation * Severe motor retardation * Severe mental retardation * Round face * Frontal bossing * Prominent glabella * Widely spaced eyes * Depressed nasal bridge * Round nasal tip * Anteverted nostrils * Low set ears * Prominent jaw * Excessive hair growth * Undescended testes * Foot defects * Contractures * Long philtrum * Thin upper lip * Cleft palate * Webbed neck * Agenesis of thumbs * Overlapping fingers * Excessive muscle tone * Sparse hair * Absent eyebrows * Absent eyelashes * Heart defects * Kidney dysgenesis * Growth retardation * Weak cry * Failure to thrive


Approximately 75% of all cases of trisomy 13 syndrome are caused by chromosomal nondisjunction. About 20% are due to chromosomal translocation involving a rearrangement of chromosomes 13 and 14. About 5% are estimated to be mosaics; the clinical effects in these cases may be less severe. Incidence is estimated to be 1 in every 5,000 neonates. The risk of chromosomal abnormalities typically increases with advanced maternal age; however, the mean maternal age for this abnormality is about 31 years.


This medical information about signs and symptoms for Chromosome 16q, partial duplication has been gathered from various sources, may not be fully accurate, and may not be the full list of Chromosome 16q, partial duplication signs or Chromosome 16q, partial duplication symptoms. Furthermore, signs and symptoms of Chromosome 16q, partial duplication may vary on an individual basis for each patient. Only your doctor can provide adequate diagnosis of any signs or symptoms and whether they are indeed Chromosome 16q, partial duplication symptoms.