Multiple malformation syndromes

Multiple malformation syndromes

Multiple malformation syndromes

On this page

Intro & Associations - Alphabet Soup Syndromes

  • Non-random clustering of malformations without a single, defined unifying cause.
  • Represents associations, not sequences or syndromes with known chromosomal/gene defects (exception: CHARGE).
MnemonicFeatures
VACTERLVertebral, Anal atresia, Cardiac, Tracheo-Esophageal fistula, Renal, Limb
CHARGEColoboma, Heart defects, Atresia choanae, Retardation (Growth), Genital hypoplasia, Ear anomalies
MURCSMüllerian duct, Renal & Cervicothoracic Somite abnormalities

CHARGE Syndrome: Facial features, coloboma, ear abnormality

Common Trisomies - Triple Chromosome Trouble

SyndromeChromosomeKey Features
Down SyndromeTrisomy 21📌 Drinking age at 21.
Flat facies, single palmar crease, sandal gap, Brushfield spots, duodenal atresia, endocardial cushion defect. Intellectual disability.
Edwards SyndromeTrisomy 18📌 Election age at 18.
Micrognathia, low-set ears, clenched hands (overlapping fingers), rocker-bottom feet. Congenital heart defects (VSD).
Patau SyndromeTrisomy 13Midline defects: Holoprosencephaly, microphthalmia, cleft lip/palate, polydactyly, cutis aplasia (scalp defects). Severe intellectual disability.

Microdeletions - Key Genetic Gaps

  • DiGeorge Syndrome (22q11.2 deletion):

    • 📌 CATCH-22: Cardiac defects (ToF), Abnormal facies, Thymic hypoplasia, Cleft palate, Hypocalcemia.
    • Defective 3rd/4th pharyngeal pouch development.
  • Williams Syndrome (7q11.23 deletion):

    • "Elfin" facies, intellectual disability, extreme friendliness.
    • Supravalvular aortic stenosis, transient hypercalcemia.
  • Prader-Willi & Angelman (15q11-q13 deletion):

    • Prader-Willi: Paternal deletion. Neonatal hypotonia, hyperphagia, obesity.
    • Angelman: Maternal deletion. "Happy puppet," seizures, ataxia.
  • Cri-du-chat Syndrome (5p deletion):

    • High-pitched, cat-like cry.
    • Microcephaly, hypertelorism.

High-Yield Fact: Fluorescence In Situ Hybridization (FISH) is the gold-standard diagnostic test for detecting microdeletions, as they are often too small for standard karyotyping.

image

Neurocutaneous Syndromes - Skin & Brain Clues

Also known as Phakomatoses, these genetic disorders affect the skin, nervous system, and other organs.

SyndromeGeneSkin ManifestationsCNS & Ocular Manifestations
Neurofibromatosis 1NF1 (Chr 17)Café-au-lait spots (>6), Axillary/inguinal freckling, NeurofibromasOptic Glioma, Lisch nodules (iris hamartomas)
Neurofibromatosis 2NF2 (Chr 22)Fewer skin signsBilateral Vestibular Schwannomas, Juvenile cataracts
Tuberous SclerosisTSC1/TSC2Ash-leaf spots (hypopigmented), Shagreen patch, Adenoma sebaceumCortical tubers, Subependymal Giant Cell Astrocytoma (SEGA)
Sturge-Weber SyndromeGNAQ (Somatic)Port-wine stain (V1/V2 distribution)Leptomeningeal angioma, Glaucoma, Tram-track calcifications

📌 Mnemonic for Tuberous Sclerosis: HAMARTOMAS (Hamartomas, Angiofibromas, Mitral regurgitation, Ash-leaf spots, Rhabdomyoma, TSC, Autosomal dominant, Mental retardation, Shagreen patch).

⭐ For Neurofibromatosis type 1, the diagnosis requires ≥2 of the key clinical features (e.g., ≥6 café-au-lait macules, ≥2 neurofibromas, axillary freckling, optic glioma, etc.).

High‑Yield Points - ⚡ Biggest Takeaways

  • VACTERL is a non-random association of defects, not a true syndrome.
  • CHARGE syndrome is linked to CHD7 gene mutations; key features are coloboma and choanal atresia.
  • DiGeorge syndrome (22q11.2 deletion) causes CATCH-22 findings: cardiac anomalies, thymic aplasia, and hypocalcemia.
  • Trisomy 18 (Edwards) shows clenched hands with overlapping fingers and rocker-bottom feet.
  • Trisomy 13 (Patau) is marked by severe midline defects like holoprosencephaly.
  • Beckwith-Wiedemann syndrome presents with macrosomia, macroglossia, and omphalocele, with a risk of Wilms' tumor.

Practice Questions: Multiple malformation syndromes

Test your understanding with these related questions

A 32-year-old woman, gravida 2, para 1, at 14-weeks' gestation comes to the physician for a prenatal visit. Routine first trimester screening shows increased nuchal translucency, decreased β-hCG concentration, and decreased levels of pregnancy-associated plasma protein A. Amniocentesis shows trisomy of chromosome 13. This fetus is at increased risk for which of the following?

1 of 5

Flashcards: Multiple malformation syndromes

1/10

DiGeorge syndrome is characterized by an absent _____ on CXR

TAP TO REVEAL ANSWER

DiGeorge syndrome is characterized by an absent _____ on CXR

thymic shadow

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial