18º Congresso Brasileiro de Neurologia Infantil

Dados do Trabalho



Apresentação do caso

AMP, 3 years old, male, lower limb hypotonia, renal tubular acidosis, hyperparathyroidism and rickets. Chitotriosity increased in previous exams. Bilaterally altered renal parenchyma, calyceal dilatation and small dilatation of the left renal pelvis. Mild metabolic acidosis, hyponatremia, hypophosphatemia, elevated urea, microalbuminuria, elevated proteinuria/creatinuria ratio, and thyroid-stimulating hormone in the upper limit. Slit lamp examination with corneal deposits of cystine crystals. Normal ENMG. Reduced tone in all four limbs, more so in lower limbs. Multidisciplinary follow-up with nephrology, endocrinology, nutrition, speech therapy and gastroenterology to better clarify the current situation, in addition to severe chronic malnutrition and eating errors identified in this hospitalization. Previous use of calcium carbonate, sodium bicarbonate and vitamin D. Adjusted sodium bicarbonate doses, started phosphorus replacement and discussed plan with multidisciplinary team for other conducts.


Infantile cystinosis, lysosomal cystine storage disease, is the most common form of cystinosis, affecting 1 in 100,000 to 200,000 children aged 3 to 6 months. Cystine, an oxidized dimer of the amino acid cysteine derived from the degradation of proteins in lysosomes, accumulates within them due to changes in the CTNS gene that encodes cystinosine, a protein that transports cystine, forming crystals with consequent renal and extrarenal signs and symptoms resulting from cell injury and tissue. Patients present with myopathy with generalized muscle atrophy and weakness, especially in distal muscles, in addition to normal cognitive function to mild neurocognitive abnormalities. Diagnosis is made by demonstration of cystine crystals in the cornea by slit lamp examination; genetic testing for pathological variants of CTNS; elevated free cystine in leukocytes or fibroblasts. Therapy includes liquid and electrolyte phosphorus, vitamin D replacement and maintenance; cysteamine as soon as diagnosis is confirmed and kidney transplantation for those who progress to end-stage renal disease.

Comentários finais

Early initiation and sustained therapy with cysteamine are essential to improve morbidity and mortality, justifying the importance of early diagnosis, however, the context of limited access to both diagnostic methods and cysteamine interferes with this outcome. The involvement of multiple systems represents a challenge for patients and for professionals and caregivers in this pathology.

Referências (se houver)

Patrick Niaudet, MD. Cystinoses. Uptodate, 11 de março de 2022 . Disponível em: <https://www.uptodate.com/contents/cystinosis?search=cistinose%20&usage_type=default&source=search_result&selectedTitle=1~29&display_rank=1>. Acesso em: 22/05/2023.

Palavras Chave

Cystinosis; Infantile Cystinosis; inborn error of metabolism

Fonte de Fomento (se houver)

Declaração de conflito de interesses de TODOS os autores

I declare that there is no conflict of interest


Erros inatos do metabolismo


Hospital da Criança Conceição - Rio Grande do Sul - Brasil


Thaís Sena Mombach Barreto, Sócrates Salvador, Anelise Uhlmann