Which of the following diseases is characterized by rocker-bottom feet?

Appeared in: DSSSB October 2024

Explanation

Trisomy 18, also known as Edwards syndrome, is the correct answer as it is classically characterized by rocker-bottom feet.
This foot deformity involves a convex sole and a prominent heel (calcaneus), giving it an appearance similar to the runner of a rocking chair.
Other key features of Trisomy 18 include clenched hands with overlapping digits, a prominent occiput, micrognathia, and severe congenital heart defects.
The association of rocker-bottom feet with Trisomy 18 is a well-documented and recognizable clinical sign used in neonatal assessment.

Option B: Trisomy 21 (Down syndrome) is not characterized by rocker-bottom feet. Its classic features include a flat facial profile, upslanting palpebral fissures, a single palmar crease, and hypotonia.
Option C: While rocker-bottom feet can occasionally be seen in Trisomy 13 (Patau syndrome), it is not considered a primary or classic characteristic. Patau syndrome is more defined by severe midline defects like holoprosencephaly, cleft lip and palate, and polydactyly.
Option D: Full Trisomy 15 is extremely rare in live births and is generally considered incompatible with life, typically resulting in early miscarriage. It is not recognized as a syndrome with characteristic features like rocker-bottom feet.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Clinical features of chromosomal trisomies as background academic context rather than a clinical decision trigger.
Recognizing dysmorphic features like rocker-bottom feet is a critical nursing skill for the early identification of potential genetic syndromes.
An early diagnosis allows for prompt genetic counseling for the family, helping them understand the prognosis and make informed decisions about care.
For conditions like Trisomy 18 and 13 with a poor prognosis, the nursing focus shifts to palliative care, ensuring the infant's comfort and providing comprehensive emotional and psychosocial support to the family.

How to Approach the Question

First, identify the key clinical sign in the question stem, which is 'rocker-bottom feet'.
This is a factual recall question that requires knowledge of the physical characteristics of different genetic syndromes.
Systematically review the options provided, which are all chromosomal trisomies.
Recall or deduce the classic findings for each trisomy. Associate Trisomy 18 (Edwards) with clenched hands and rocker-bottom feet.
Associate Trisomy 21 (Down) with features like a flat face and single palmar crease.
Associate Trisomy 13 (Patau) with severe midline defects like clefting and polydactyly.

Concept Tested & Keywords

QULwbeEqtVFtY7iji-kKyi

E6 Obstetrics Williams p. 5-16

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 408-410

Practise the full DSSSB October 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.