Page 208 - Concise Pathology for Exam Preparation ( PDFDrive )

8 Genetic and Paediatric Disorders 193

Clinical Features

• Mental retardation (IQ 5 25–40).
• Flat facial profile and epicanthic folds, oblique palpebral fissure (Mongolism/Mongolian
idiocy).
• Abundant neck skin.
• Congenital heart defects like atrial septal defects, endocardial cushion defects, atrioven-
tricular valve malformations and ventricular septal defects (major cause of death during
early life).
• Umbilical hernia.
• Intestinal stenosis.
• Hypotonia; gap between the first and second toe.
• Simian crease.
• Predisposition to acute leukaemia (lymphoblastic and myeloblastic).
• Neuropathological changes (like Alzheimer disease), seen after the age of 40 years.

Q. Write briefly on Edwards syndrome.

Ans. Edwards syndrome is a cytogenetic disorder affecting chromosome 18.

Incidence
1 in 8000 live births.

Genetic Abnormalities
Trisomy of chromosome 18 (47, XX, 118); mosaic type—46, XX/47, XX, 118.

Clinical Features

• Mental retardation
• Micrognathia
• Prominent occiput
• Low-set ears
• Short neck
• Congenital heart defects
• Renal malformations
• Limited hip abduction
• Overlapping of fingers
• Rocker bottom feet

Q. Write briefly on Patau syndrome.

Ans. Patau syndrome is a cytogenetic disorder affecting chromosome 13.

Incidence
1 in 15,000 live births.

Genetic Abnormalities

Trisomy of chromosome 13 (47, XX, 113); mosaic type—46, XX/47, XX, 113; transloca-
tion type—46, XX, 113, der(13;14)(q10;q10).

Clinical Features
• Microcephaly and mental retardation.
• Microphthalmia.
• Cleft lip and palate.

mebooksfree.com