Table 1

Cytogenetic and clinical features of cases with complete and partial tetrasomy 21

Case reportRef. 4Ref. 5Ref. 6Ref. 7Ref. 8This case
NI, no information; NL, normal; +, symptom present; (+), symptom present with less characteristic features; −, symptom absent.
Peripheral blood lymphocytes48,XY, +21,+2147,XX, +idic(21)(q22.1)47,XY,+psu idic(21)(q22.1)47,XY,+psu dic(21;21) (q22.11;q22.11)47,XY,+psu idic(21)(q22.1)47,XY,+psu idic(21)(q21.1)
Parental chromosomesNormalMaternal studies normalNormalNormalNormalNormal
Mother’s age24 years32 years33 years46 years34 years33 years
Father’s age36 earsNI32 years52 years33 years40 years
PregnancySpotting/coughNormalBleedingNI↓weight gainNormal
Gestation32 weeksTerm38 weeksNI33 weeksTerm (39 weeks)
Birth weight (g)202029403600330014203690 g
Age at referral4 days33 months29 months9.2 years18 month27 months
LengthNI89.5 cm (25th)90 cm (50th)NL range68 cm (<3rd)85 cm (3rd–10th)
WeightNI12.0 kg (10th)10.9 kg (10th)NL range8.88 kg (<3rd)11 kg (3rd–10th)
Head circumferenceNI45.5 cm (<3rd)45.5 cm (<3rd)NL range40.3 cm (<3rd)47 cm (<3rd)
Motor developmentNINormalUnable to walkRetardedUnable to sitRetarded
SpeechNISingle wordsBabbleSingle words
Jackson Score91071125
Brachycephaly+++++
Upslanted palpebral fissures++++
Epicanthal folds++
Brushfield spotsNI+(+)
Flat nasal bridge+++(+)
Open mouthNI++++
Protruding tongueNI+++
Furrowed tongueNI
Ears small/low set+
Short neck+++
Excess nuchal skin++
Short and broad handsNI++
Short fifth fingerNI++(+)
Transverse palmar crease+
Gap between 1st and 2nd toes+(+)
Congenital heart defectPDA
Muscular hypotonia+++NI++