- Triple X syndrome (karyotype 47,XXX)

Triple X syndrome (karyotype 47,XXX)

Also called trisomy X

This affects 1 in 1000 live-born girls.

These patients show little phenotypic abnormality mostly hypertelorism and clinodactyly  but tend to be of tall stature.

Although intelligence is typically reduced compared with siblings it usually falls within normal or low–normal limits.

However, mild developmental and behavioral difficulties are more common. Fertility is normal but the incidence of early menopause is increased.

Delayed development of motor skills (such as sitting and walking), hypotonia, and behavioral and emotional difficulties are also possible, but these characteristics vary widely.

Seizures or kidney abnormalities occur in about 10 percent of affected females.

Treatment for triple X syndrome depends on which symptoms, if any, are present and their severity.

- Edwards syndrome and Patau syndrome

 

Trsiomy 18 and Trisomy 13

Trisomy 13 (Patau syndrome)	Trisomy 18 (Edwards syndrome)
1/ 14000 ( female = male)	1/8000 ( female > male)	incidence
Severe MR		neurological
Hypo or hypertonia Holoprosencephaly (single hemisphere with single ventricle)	Hypertonia
Microcephaly		head
Sloping forehead Scalp defects	Prominent occiput
Micrognathia, dysplastic Low set ears		face
Midline Cleft lip and palate
Eye anomalies (cataract, coloboma, micropthalmia (small eye) and corneal opacities) Closely-spaced eyes, single central eye (cyclopia)	Small palpebral fissure
polydactaly	Clenched fist Rocker bottom clinodactyly,  overlapping fingers (second and fifth overlap third and fourth)	extremities
Cardiac (88%),: VSD or PPA	Cardiac (99%):  vsd , pda	Associated malformations
renal
Pre & post-natal growth retardation		growth
Some 50% of babies die in the first month and most of the rest in the first year. Survival beyond early infancy is rare and associated with profound learning disability.	Only 5% lives > 1year and associated with profound learning disability. Most babies die in the first year of life.	Life expectancy
confirmed by chromosome analysis. Many affected fetuses are detected by ultrasound scan during the second trimester of pregnancy and diagnosis can be confirmed antenatally by amniocentesis and chromosome analysis.  Can also be diagnosed on non-invasive prenatal testing (NIPT).		diagnosis
Recurrence risk is low, except when the trisomy is due to a balanced chromosome rearrangement in one of the parents.		Recurrence risk