Successful Surgical Sperm Extraction in a Patient With Cystinosis

Cystinosis is a genetic lysosomal storage disease with an autosomal recessive inheritance pattern. The mutation causing this disease occurs in the <i>CTNS</i> gene, which is located on chromosome 17 and codes for the lysosomal cystine transporter cystinosin. Cystinosis is characterized by intracellular accumulation of cystine in various organs and tissues, which may lead to impairment of organ function. Kidney injury is characterized by a progressive decline in glomerular filtration rate, leading to end-stage kidney disease if not treated. Other manifestations of cystinosis include ocular abnormalities, hepatomegaly, hypothyroidism, muscle weakness, and growth retardation. Male patients with cystinosis typically have azoospermia, and current data regarding the existence of spermatogenesis and the possibility of surgical sperm retrieval in these patients are limited. This article presents a case of a male patient in his thirties with cystinosis and azoospermia who presented for evaluation and treatment of infertility. His serum testosterone was normal, but gonadotropin levels were markedly elevated. Y chromosome micro-deletion assay was negative, and the karyotype was normal. Testicular sperm extraction revealed the presence of viable mature sperm that were successfully harvested and cryopreserved. The patient's spouse conceived through an in vitro fertilization cycle that utilized the patient's surgically retrieved sperm and subsequently delivered a healthy baby boy. This case report provides novel information on post-thaw quality measures of sperm that were surgically retrieved from a patient with cystinosis, as well as on outcomes of in vitro fertilization that utilized such sperm. The post-thaw quality of sperm is associated with its utility for in vitro fertilization and thus adds to the limited data available thus far regarding the feasibility of surgical sperm retrieval in patients with this disease.