Makindo Medical Notes

Related Subjects: | Osteoporosis | Autosomal Dominant | Autosomal Recessive | X Linked Recessive |Dementias |Chromosomal Defects |Turner's syndrome (Children) |Down's syndrome (Children)

⬇️ Down Syndrome (Trisomy 21)

• Genetic: Extra chromosome 21
• Incidence: ~1 in 700 births
• Key Features: Intellectual disability 🧠, hypotonia, characteristic facies 🙂, congenital heart disease ❤️
• Additional: ↑ risk of acute leukemia, early-onset Alzheimer disease

♀️ Turner Syndrome (45, X0)

• Genetic: Monosomy X (missing one X chromosome)
• Incidence: ~1 in 2500 female births
• Key Features: Short stature 📏, webbed neck, streak ovaries → infertility, cardiovascular anomalies ❤️
• Additional: Phenotypic females only, may need estrogen therapy

♂️ Klinefelter Syndrome (47, XXY)

• Genetic: Extra X chromosome (XXY)
• Incidence: ~1 in 650 male births
• Key Features: Tall stature 📏, hypogonadism, infertility, learning difficulties, gynecomastia
• Additional: Often undiagnosed until puberty, testosterone replacement may help

🎵 Williams Syndrome (7q11.23 Deletion)

• Genetic: Deletion at 7q11.23
• Incidence: ~1 in 10,000 births
• Key Features: “Elfin” facies 🧚, intellectual disability, hypercalcemia, cardiovascular issues ❤️
• Additional: “Cocktail party” personality 🍸, verbal skills stronger than visuospatial

😄 Angelman Syndrome

• Genetic: Maternal deletion at 15q11-q13
• Incidence: ~1 in 12,000–20,000 births
• Key Features: Severe intellectual disability 🧠, ataxia 🚶, seizures ⚡, frequent laughter 😂
• Additional: Historic term “happy puppet syndrome”, profound speech impairment

🍽️ Prader-Willi Syndrome

• Genetic: Paternal deletion at 15q11-q13
• Incidence: ~1 in 10,000–30,000 births
• Key Features: Neonatal hypotonia 🍼, hyperphagia 🍔 → obesity, short stature 📏, small hands/feet
• Additional: ↑ risk of type 2 diabetes, behavioural issues common

🧩 DiGeorge Syndrome (22q11.2 Deletion)

• Genetic: Deletion at 22q11.2
• Incidence: ~1 in 4000 births
• Key Features: Congenital heart defects ❤️, cleft palate 👄, thymic aplasia 🦠 → immunodeficiency, hypocalcemia
• Additional: Also called “22q11.2 deletion syndrome”, T-cell deficiency possible

👶 Edwards Syndrome (Trisomy 18)

• Genetic: Extra chromosome 18
• Incidence: ~1 in 6000 births
• Key Features: Severe intellectual disability 🧠, clenched hands ✊, rocker-bottom feet 👣, congenital heart disease ❤️
• Additional: High infant mortality, micrognathia, low-set ears

👶 Patau Syndrome (Trisomy 13)

• Genetic: Extra chromosome 13
• Incidence: ~1 in 10,000 births
• Key Features: Severe intellectual disability 🧠, polydactyly 🖐️, holoprosencephaly, cleft lip/palate 👄
• Additional: Often fatal in early infancy, congenital heart defects common