Trisomy 8
Epidemiology
and Etiology:
·
Rare
·
Most are mosaics
·
M:F = 2-3:1
·
Maternal meiosis 1
usually
Gross
Features:
·
Craniofacial dysmorphism
o Prominent forehead
o Deep-set eyes
o Strabismus
o Broad nasal bridge
o Upturned nares
o Long upper lip
o Thick and everted lower lip
o High arched or cleft palate
o Micrognathia
o Large dysplastic ears with prominent antihelices
·
Skeletal
abnormalities
o Long, thin trunk
o Hemivertebrae
o Spina bifida
o Kyphoscoliosis
o Hip dysplasia
o Multiple joint contractures
o Camptodactyly (permanent flexure of one or more phalanges)
o Dysplastic nails
o Absent or dysplastic patella
·
deep palmar and plantar furrows (characteristic)
·
renal and ureter anomalies commonly
·
congenital heart
defects commonly
·
Growth variable
Molecular
features:
·
?often not detected
in the blood ?disappears over time (double check this)
Other
Features:
·
Clinical features:
o Mental retardation
§ Mild to severe
§ A proportion have normal IQs
·
Complications:
o Hematological malignancy has been reported
·
Genetic Counselling:
o Recurrence risk is unkown
References:
·
Gersen SL,