Dados do Trabalho

Título

Neurofibromatosis type I in association with Duchenne muscular dystrophy: Case report

Apresentação do caso único

Case Presentation

Patient C.L.S., male, 11 years old, from Santo André, São Paulo, with previous diagnosis of neurofibromatosis type 1 based on clinical criteria and a positive family history, was referred to the pediatric neurology clinic with complaints of progressive lower limb weakness that significantly worsened over the past 4 months, rendering him unable to walk.
At age three, the patient exhibited an equinus gait and was evaluated by the pediatric orthopedics team at another institution, attributing the condition to tendon shortening, which led to surgical intervention at age six in 2019. Post-surgery, the patient experienced a progressive decline in ambulation, difficulty climbing stairs and standing up, and frequent falls.
Given the diagnosis of neurofibromatosis type 1, an investigation was conducted to rule out compressive lesions and tumors.
Cognitively, C.L.S. presented learning difficulties and is currently at the pre-literacy stage.

Clinical findings:
Skin inspection revealed axillary and inguinal freckling and 10 café-au-lait spots larger than 5mm.
Mild hypotrophy of the lower limbs with muscle strength graded II, hyporeflexia, and inability to walk.
Upper limbs showed no abnormalities.
Presence of Lisch nodules confirmed by slit-lamp examination.
A creatine phosphokinase (CPK) level of 3688 was noted. Subsequent broad DNA panel testing for neuromuscular diseases identified a hemizygous nonsense mutation in the DMD gene, leading to a diagnosis of dystrophinopathy.

Discussão

Discussion

Neurofibromatosis type 1 is an autosomal dominant genetic condition caused by mutations in the NF1 gene on chromosome 17, impairing the tumor suppressor protein neurofibromin.
Duchenne Muscular Dystrophy (DMD) is an X-linked recessive genetic disorder resulting from mutations in the dystrophin gene, characterized by progressive muscle weakness usually beginning in early childhood.
Both conditions share overlapping behavioral and neurocognitive issues but differ significantly in their clinical and genetic manifestations.

Comentários finais

Final Comments

This case highlights the necessity of individualized evaluation of the clinical progression, regardless of the patient's underlying condition. If there is an alteration in the natural course of the disease, differential diagnoses should be considered, and further investigations should be conducted to avoid delayed diagnoses.

Referências

Hellebrekers DMJ, van Abeelen SAM, Catsman CE, van Kuijk SMJ, Laridon AM, Klinkenberg S, Hendriksen JGM, Vles JSH. Cognitive and behavioral functioning in two neurogenetic disorders; how different are these aspects in Duchenne muscular dystrophy and Neurofibromatosis type 1? PLoS One. 2022 Oct 10;17(10):e0275803. doi: 10.1371/journal.pone.0275803. PMID: 36215287; PMCID: PMC9551631.

LLy KI, Blakeley JO. The Diagnosis and Management of Neurofibromatosis Type 1. Med Clin North Am. 2019 Nov;103(6):1035-1054. doi: 10.1016/j.mcna.2019.07.004. PMID: 31582003.

Yohay K. Neurofibromatosis type 1 and associated malignancies. Curr Neurol Neurosci Rep. 2009 May;9(3):247-53. doi: 10.1007/s11910-009-0036-3. PMID: 19348714.

Duan D, Goemans N, Takeda S, Mercuri E, Aartsma-Rus A. Duchenne muscular dystrophy. Nat Rev Dis Primers. 2021 Feb 18;7(1):13. doi: 10.1038/s41572-021-00248-3. PMID: 33602943; PMCID: PMC10557455.

Palavras Chave

Neurofibromatosis Type 1 (NF1); Duchenne muscular dystrophy; genetic disorder