Fanconi anemia in a 10-year-old girl: Unusual multisystem manifestations with bilateral ectopic kidneys and a novel FANCA mutation

Fanconi anemia (FA), a rare DNA repair disorder, presents diagnostic challenges due to its heterogeneous clinical spectrum. This report details the novel case of a 10-year-old female with FA exhibiting an unprecedented combination of pancytopenia, thumb hypoplasia (Blauth type 4), and bilateral ectopic kidneys with severe hydronephrosis – features expanding FA’s phenotypic and renal anomaly profile. Clinical evaluation revealed hypocellular bone marrow, absent thumb metacarpal, and markedly reduced renal function (right kidney glomerular filtration rate: 10.5%), alongside characteristic hyperpigmentation and short stature. Genetic analysis identified a homozygous pathogenic frameshift variant in FANCA (c. 2265dup; p.Arg756fs*13), a novel mutation linked to FA. This case underscores the diagnostic complexity of FA in children with multisystem anomalies and highlights the importance of integrating genetic testing for early confirmation, particularly when atypical renal malformations coexist. The bilateral ectopic kidneys, a rarely reported FA feature, emphasize the need for vigilant renal surveillance to mitigate progressive dysfunction. Early diagnosis enabled timely planning for hematopoietic stem cell transplantation (HSCT), critical for preventing hematologic progression. Furthermore, this report reinforces FA’s heightened post-HSCT solid tumor risk, necessitating lifelong multidisciplinary monitoring. By illustrating the interplay of hematologic, skeletal, and renal manifestations, this case advances the understanding of FA’s diverse presentation and informs strategies for holistic management, blending genetic insights with organ-specific interventions to optimize the outcomes in this high-risk population.