Table 4 Viable aneuploidies
AneuploidyCommon nameEstimated incidence among life-birthsSymptoms can include
Trisomy 13Patau syndromeApproximately 1:16000Severe intellectual disability, heart defects, brain or spinal cord abnormalities, small or poorly developed eyes, extra fingers or toes, cleft lip and palate, weak muscle tone
Trisomy 18Edwards syndromeApproximately 1:5000Intrauterine growth retardation, low birth weight, heart defects and abnormalities of other organs, small, abnormally shaped head, small jaw and mouth, clenched fists, severe intellectual disability
Trisomy 21Down syndromeApproximately 1:800Mild to moderate intellectual disability, characteristic facial appearance, weak muscle tone, heart defects, digestive abnormalities, hypothyroidism, increased risk of hearing and vision problems, leukaemia, Alzheimer’s disease
Trisomy XTriple X syndromeApproximately 1:1000Increased height, increased risk of learning disabilities, delayed development of speech, language and motor skills, weak muscle tone, behavioural and emotional difficulties, seizures, kidney abnormalities
47,XYYApproximately 1:1000Increased height, increased risk of learning disabilities, delayed development of speech, language, and motor skills, weak muscle tone, hand tremors, seizures, asthma, scoliosis, behavioural and emotional difficulties
47,XXYKlinefelter syndrome1:500 to 1:1000Small testes, low testosterone levels, delayed and incomplete puberty, breast enlargement, reduced facial and body hair, infertility, increased height, increased risk of breast cancer, learning disabilities, delayed speech and language development
48,XXXYApproximately 1:18000 to 1:40000Small testes, low testosterone levels, delayed and incomplete puberty, breast enlargement, reduced facial and body hair, infertility, increased height, tremors, dental problems, peripheral vascular disease, deep vein thrombosis, asthma, type 2 diabetes, seizures, heart defects, delayed speech and language development, learning disabilities
45,XTurner syndromeApproximately 1:2500Short stature, early loss of ovarian function, infertility, absence of puberty, webbing of the neck, skeletal abnormalities, kidney problems, heart defects
  • Common names are given, where available, together with estimated incidence rates and symptoms frequently associated with the condition.