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Table 1 Summary of the most important phenotypic aspects of the discussed chromosomal abnormalities

From: What should we consider in the case of combined Down- and 47,XY,+i(X)(q10) Klinefelter syndromes? The unique case of a male newborn and review of the literature

DSKSi(X)(q10) KSPredicted phenotypePatient’s signs
Prenatal signs
↑↑: increased maternal serum marker levels (PAPP-A, uE3, total & free β-hCG); ultrasound signs (hypoplastic nasal bone, >3mm nuchal translucency, abnormal ductus venosus flow, oligo-/polyhydramnios, 5th finger brachymesophalangy, ventriculomegaly, short femur & humerus)[SGA: increases with number of extra X chromosomes][− SGA]↑↑: increased maternal serum marker levels (PAPP-A, uE3, total & free β-hCG); ultrasound signs (hypoplastic nasal bone, >3mm nuchal translucency, abnormal ductus venosus flow, oligo-/polyhydramnios, 5th finger brachymesophalangy, ventriculomegaly, short femur & humerus) [SGA]no signs
Nervous sys.
↑↑: ID/DD; epilepsy↑: moderate ID: increases with number of extra X chromosomes; mild language problems; deficits in executive functions; smaller total brain/gray & white matter volume[mild language problems?; deficits in executive functions?; smaller total brain/gray & white matter volume?]↑↑: ID/DD; epilepsy; mild language problems?; deficits in executive functions?; smaller total brain/gray & white matter volume?no signs
Mental & socioeconomic status
↑↑: autism spectrum disorder; good mood; Alzheimer’s disease; poorer mental & physical quality of life↑↑: anxiety; depression; behavioral disorders; poorer mental & physical quality of life↑↑: anxiety; depression; behavioral disorders; poorer mental & physical quality of life↑↑↑↑: autism spectrum disorder; Alzheimer’s disease; anxiety, emotional & behavioral disorders; poorer mental & physical quality of lifeno signs
Musculosceletal & connective tissue sys.
↑↑: connective tissue weakness (rectus diasthasis, inguinal/umbilical hernia); joint hypermobility; muscle hypotonia↑↑: low muscle mass/strength/tone; early & more pronounced osteopenia/-porosis↑↑: low muscle mass/strength/tone; early & more pronounced osteopenia/-porosis↑↑↑: connective tissue weakness (rectus diasthasis, inguinal/umbilical hernia); joint hypermobility; muscle hypotonia, low muscle mass/strength/tone; early & more pronounced osteopenia/-porosisrectus diasthasis, umbilical hernia, muscle hypotonia
Hearing impairment
↑↑: sensorineural/ conductive (frequent middle ear inflammation)[not typical][not typical]↑↑: sensorineural/ conductive (frequent middle ear inflammation)no signs
Ophthalmic anomalies
↑↑: Brushfield’s macules, cataract, glaucoma, keratoconus, strabismus, refractive errors[not typical][not typical]↑↑: Brushfield’s macules, cataract, glaucoma, keratoconus, strabismus, refractive errorsno signs
Cardiovascular sys.
↑↑: AVSD; VSD; Fallot tetralogy; mitral valve problems↑: hypertension; higher risk for DVT & PE; short QTc↑: hypertension; higher risk for DVT & PE↑↑↑: AVSD; VSD; Fallot tetralogy; mitral valve problems
↑: hypertension; higher risk for DVT & PE
no signs
Immune sys.
↑↑: increased suscept. to infections↑↑: increased suscept. to autoimmune diseases (SM, RA, Hashimoto’s disease, Sjögren’s syndrome, SLE, T1DM)↑↑↑: increased suscept. to autoimmune diseases (SM, RA, Hashimoto’s disease, Sjögren’s syndrome, SLE,T1DM)↑↑↑↑: increased suscept. to infections & autoimmune diseasesno signs
Endocrine sys.
↑↑: congenital primary hypothyroidism; T1DM/T2DM↑↑: hypergonadotropic hypogonadism; metabolic syndrome (T2DM, hypertension, dyslipidemia)↑↑: hypergonadotropic hypogonadism; metabolic syndrome↑↑: congenital primary hypothyroidism; T1DM/T2DM; hypergonadotropic hypogonadism; metabolic syndromeno signs
Gastrointestinal sys.
↑↑: constipation, decreased appetite, Hirschprung’s disease, pyloric stenosis, duodenal atresia, Meckel’s diverticulum, anal atresia, celiac disease, gastroesophageal reflux disease[not typical][not typical]↑↑: decreased appetite, constipation, Hirschprung’s disease, pyloric stenosis, duodenal atresia, Meckel’s diverticulum, anal atresia, celiac disease, gastroesophageal reflux diseasemoderate appetite
Oropharyngeal abnormalities
↑: necrotizing ulcerative gingivitis, periodontitis, early tooth loss, malocclusion, late teething, small teeth, dental enamel hypocalcification, cheilognathopalatoschisis[not typical][not typical]↑: necrotizing ulcerative gingivitis, periodontitis, early tooth loss, malocclusion, late teething, small teeth, dental enamel hypocalcification, cheilognathopalatoschisisno signs
Fertility & sexual problems
↑↑: decreased fertility/infertility (in male: oligo/azoospermia & in female: early menopause, decreased sexual activity)↑↑: decreased fertility/infertility (oligo-/azoospermia, decreased sexual activity)↑↑: decreased fertility/infertility (oligo-/azoospermia, decreased sexual activity)↑↑↑↑: decreased fertility/infertility (oligo-/azoospermia, decreased sexual activity)no signs
Tumor predisposition
↑↑: increased risk for: testicular germ cell tumors, ALL, AML, AMKL↑: risk for: extragonadal germ cell tumors & breast cancer↑: risk for: extragonadal germ cell tumors & breast cancer↑↑↑↑: increased risk for: extragonadal germ cell & testicular tumors, ALL, ML-DSno signs
↓: risk for certain solid tumors: breast, lung, prostate↓: risk for lung & prostate cancerno signs
  1. Table legend: square brackets []: rare/non-characteristic features, ↓: decreased risk, ↑: slightly increased risk/incidence, ↑↑: moderate increased risk/incidence, ↑↑↑: expressed risk/incidence, ↑↑↑↑: very high risk/incidence, sy. syndrome, sys. system, PAPP-A pregnancy-associated plasma protein A, uE3 unconjugated oestriol, β-hCG beta human chorionic gonadotropin, SGA small for gestational age, ID intellectual disability, DD developmental delay, ? unclarified significance, AVSD atrioventricular septal defect, VSD ventricular septal defect, DVT deep vein thrombosis, PE pulmonary embolism, QTc corrected QT interval, SM sclerosis multiplex, RA rheumatoid arthritis, SLE systemic lupus erythematosus, T1DM type 1 diabetes mellitus, T2DM type 2 diabetes mellitus, ALL acute lymphoid leukemia, AML acute myeloid leukemia, AMKL acute megakaryoblastic leukemia, ML-DS myeloid leukemia of Down syndrome