FFinalistSouthampton · 2027
Child health
AKT · Child health/Genetic syndromes

Fanconi anaemia

DNA repair defect — autosomal recessive (OFF-MAP mimic)

Overview

An inherited bone-marrow failure / DNA-repair disorder. The exam exemplar: a child who LOOKS like leukaemia (pancytopenia, bruising) but has CONGENITAL anomalies — short stature, absent/hypoplastic radii and thumbs, café-au-lait spots — that flip the diagnosis away from ALL.

Recognise

  • Progressive bone marrow failure: pancytopenia (anaemia, bruising/petechiae, infections)
  • CONGENITAL anomalies: SHORT STATURE, absent/hypoplastic RADII and thumbs, café-au-lait macules, renal/microphthalmia
  • High risk of AML and solid tumours

Red flags

  • Marrow failure; transformation to AML; the congenital anomalies are the diagnostic key

Differentials & how to tell them apart

Acute lymphoblastic leukaemia (ALL)THE exam trap — also pancytopenia/bruising, but ALL has NO congenital short stature or absent radius; the skeletal anomaly flips it to Fanconi
Idiopathic aplastic anaemiano congenital anomalies
TAR syndromeabsent radii but thumbs PRESENT, isolated thrombocytopenia
Diamond-Blackfan anaemiapure red cell aplasia, thumb anomalies, no pancytopenia

Investigations

FBC/film (pancytopenia). The discriminator: chromosomal breakage test (increased breakage with diepoxybutane/mitomycin C). Bone marrow; genetics.

Management

  1. 1Supportive (transfusion, infection control); androgens may help. Definitive: haematopoietic stem cell transplant.
  2. 2Lifelong cancer surveillance (AML, solid tumours); genetic counselling.
Haematopoietic stem cell transplant — definitive for marrow failure
Androgens / supportive transfusion — temporising

Key points

THE teaching case for the resit: information-lean stem describes "classic ALL", but the single odd detail (short stature + absent/hypoplastic radius) is NOT a red herring — it is the answer key pointing to Fanconi. Integrate the odd finding.

Monitor & prognosis

Counts, marrow, malignancy surveillance.

Guarded; transplant addresses marrow failure but cancer risk persists.

Source: StatPearls; haematology (off-map exemplar)