Human Aneuploidies and Frequencies at Birth

Table 10.2 Human Aneuploidies and Frequencies at Birth Aneuploidy Syndrome Frequency at Birth Syndrome Characteristics Autosoma! Aneuploidy Trisomy 13 Patau syndrome 1 in 15,000 Mental retardation and developmental delay, possible deafness, major organ abnormalities, early death Trisomy 18 Edward syndrome 1 in 8000 Mental retardation and developmental delay, skull and facial abnormalities, early death Sex-Chromosome Aneuploidy Trisomy 21 Down syndrome 1 in 1500 Mental retardation and developmental delay, characteristic facial abnormalities, short stature, variable life span 47, XXY Klinefelter syndrome (males) 1 in 1000 Variable secondary sexual characteristics, infertility, frequent breast swelling; no impact on mental capacity 47, XYY Jacob syndrome (males) 1 in 1000 Tall stature common; possible reduction but not loss of fertility; no impact on mental capacity 47, XXX Triple X syndrome (females) 1 in 1000 Tall stature common; possible reduction of fertility; menstrual irregularity; no impact on mental capacity 45, X0 Turner syndrome (females) 1 in 5000 No secondary sexual characteristics; infertility, short stature; webbed neck common; no impact on mental capacity