Q&A: Haematological Complication of Down's Syndrome

Down syndrome (DS) is the most common chromosome abnormality among liveborn infants. It is the most frequent form of intellectual disability caused by a microscopically demonstrable chromosomal aberration. DS is characterized by a variety of dysmorphic features, congenital malformations, and other health problems and medical conditions. Not all of them are present in each affected individual.

This article is for Medical Students & Professionals

This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the What is Blood? article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Impact of Down syndrome
MCQ: clinical scenario
MCQ: answer
MCQ: explanation

Impact of Down syndrome

The impact of Down syndrome (DS) for each person is individual, with some individuals being profoundly impacted while others are healthy and able to live independently as adults. In general, individuals with DS are now reaching fuller potentials secondary to better educational programs, medical advancements, community resources, and the support of family and friends.

MCQ: clinical scenario

A 38 year old male with Down's syndrome develops shortness of breath and diffuse epistaxis. On examination he is found to have generalised large lymph nodes and hepatosplenomegaly. There are diffuse petechiae and ecchymoses, on his skin.

A Romanovsky-stained smear of his bone marrow is most likely to demonstrate:

a) Target cells
b) Melanocytes
c) Lymphoblasts with clumped chromatin
d) Transitional epithelial cells
e) Mast cell infiltration
f) Neutropenia
g) Burr cells
h) Squamous epithelial cells
i) Anti-nuclear antibodies
j) Clumps of neutrophils

MCQ: answer

The correct answer is C

MCQ: explanation

Acute leukemias are commoner in Down's syndrome. Experienced morphologists can reproducibly classify about 70% of acute leukemias as either ALL or AML by the blast appearance on Romanovsky-stained smears based on nuclear and cytoplasmic features. The most important morphologic characteristic in identifying blasts is the nuclear chromatin pattern. The chromatin in lymphoblasts is more clumped and irregularly distributed. The presence of nucleoli varies. Nucleoli may be indistinct or appear prominent because of chromatin condensation along the nucleolar and nuclear membranes.

Reference(s)
1). UpToDate: Down syndrome: Clinical features and diagnosis. Available online: https://www.uptodate.com/contents/down-syndrome-clinical-features-and-diagnosis