Genetic & Dysmorphology
Dr. Salma Elgazzar
Common Syndromes in Pediatrics
Recognize the various genetic disorders and have a basic knowledge of the appropriate diagnostic tests and clinical course for common disorders such as:
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Down Syndrome - Trisomy 21
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Edward Syndrome - Trisomy 18
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Patau Syndrome - Trisomy 13
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Turner Syndrome - 45X0
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Klinefelter Syndrome - 47, XXY
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Marfan Syndrome - Autosomal Dominant
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Williams Syndrome - 7q11.23 C band deletion
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Achondroplasia - Mutation fibroblast growth FGFR3-C4
Table
| Syndrome | Craniofacial/Physical Features | Medical Problems | Inheritance/Genetics | Other Anomalies | Treatment/Management |
|---|---|---|---|---|---|
| Down Syndrome | Round face, flat nasal bridge, upslanted palpebral fissures, epicanthic folds, small mouth, ears | Delayed motor milestones, learning difficulties, short stature, infections, hearing/visual impairments | Meiotic nondisjunction (94%), translocation (5%), mosaicism (1%) | Short neck, single palmar creases, congenital heart defects, duodenal atresia, Hirschsprung disease | Supportive therapies, early intervention programs |
| Trisomy 18 (Edward Syndrome) | Microcephaly, high forehead, rocker bottom feet, clubfoot, overlapping fingers, hypoplastic nails | Apneic episodes, poor feeding, failure to thrive, intellectual disability, heart defects (VSD, ASD, PDA) | Risk of recurrence <1%, higher with increased maternal age | None specified | Supportive care, management of symptoms |
| Trisomy 13 (Patau Syndrome) | Cleft lip/palate, polydactyly, microcephaly, microphthalmia, scalp defects | Cardiac defects (PDA, VSD), genital anomalies, neural tube defects | Risk of recurrence <1%, higher with increased maternal age | Omphalocele, hernias | Supportive care, management of symptoms |
| Turner Syndrome (45X0) | Short stature, lymphedema, shield chest, webbed neck, low posterior hairline, rotated ears | Ovarian dysgenesis, cardiac defects (bicuspid aortic valve, coarctation of aorta), renal anomalies | Absence of one set of genes from the short arm of one X chromosome | Increased risk of hypothyroidism, celiac disease, inflammatory bowel disease, gonadoblastoma | Growth hormone, estrogen therapy |
| Klinefelter Syndrome (47, XXY) | Tall stature, gynecomastia, small penis, infertility, delayed secondary sexual characteristics | Language impairment, academic difficulty, osteoporosis, hypogonadism | 47,XXY karyotype with variants | Increased risk of pulmonary disease, varicose veins, ADHD | Testosterone replacement therapy |
| Marfan Syndrome | Pectus carinatum/excavatum, wrist sign, scoliosis, high arched palate | Cardiovascular complications (aortic dilatation/dissection), ectopia lentis, dural ectasia | Autosomal dominant | Joint hypermobility, mitral valve prolapse, spontaneous pneumothorax, striae atrophicae | Annual echocardiogram, management of cardiovascular complications |
| William Syndrome (7q11.23) | Short stature, characteristic facies, periorbital fullness, prominent lower lip | Congenital heart disease (supravalvular aortic stenosis), learning difficulties, sensorineural hearing loss | Deletion at chromosome band 7q11.23 | Transient neonatal hypercalcemia, strabismus, cataract | Supportive care, management of symptoms |
| Achondroplasia | Short stature, marked shortening of limbs, large head, frontal bossing, depression of nasal bridge | Hydrocephalus, marked lumbar lordosis | Mutation in FGFR3 gene on chromosome 4, autosomal dominant, 50% new mutations | None specified | Growth hormone, limb lengthening |