Received by the Editorial Office: June 06, 2026
Accepted for publication: August 02, 2026
Published online: September 30, 2026
UDC: 616-056.7-053.2:616.24-008.444
DOI: 10.26212/2227-1937.2026.13.70.004
Article type: Case Report / Clinical Case
A CLINICAL CASE OF SEVERE OBSTRUCTIVE SLEEP APNOEA SYNDROME IN A PATIENT WITH HUNTER SYNDROME
Tulebayeva A.K.¹, Sharipova M.N.², Kurmanbekova S.K.¹
¹ Asfendiyarov Kazakh National Medical University, Almaty, Kazakhstan
² Scientific Center of Pediatrics and Pediatric Surgery, Almaty, Kazakhstan
Introduction. Hunter syndrome (mucopolysaccharidosis type II) is a rare X-linked lysosomal storage disorder caused by iduronate-2-sulfatase deficiency due to pathogenic variants in the IDS gene. Progressive glycosaminoglycan accumulation results in multisystem involvement, including upper-airway obstruction. Obstructive sleep apnoea syndrome (OSAS) is a clinically important and potentially life-threatening complication.
Objective. To describe a case of severe OSAS in a child with the severe neuropathic form of Hunter syndrome and to highlight the clinical importance of timely detection of sleep-disordered breathing.
Materials and Methods. Clinical data from a 12-year-old child with Hunter syndrome confirmed by enzyme activity assay and molecular genetic testing were analyzed. The comprehensive evaluation included physical examination, echocardiography, electrocardiography, chest radiography, brain computed tomography, and overnight respiratory monitoring using the SOMNOcheck Micro CRADIO cardiorespiratory system. OSAS severity was assessed using the apnoea-hypopnoea index (AHI).
Results. The patient had a severe neuropathic phenotype with marked psychomotor and growth delay, grade III adenoid hypertrophy, macroglossia, Mallampati class IV, multiple skeletal deformities, hepatomegaly, and central nervous and cardiovascular system involvement. Overnight monitoring demonstrated severe OSAS: AHI 45.6 events/h, longest apnoea 2 min 30 s, minimum SpO₂ 78%, and 280 apnoea episodes during the night.
Discussion. This case illustrates that, in the neuropathic form of Hunter syndrome, anatomical upper-airway narrowing, glycosaminoglycan deposition in soft tissues, and multisystem disease may contribute to severe sleep-disordered breathing. A single case cannot be generalized to the broader Hunter syndrome population; however, it underscores the need for active OSAS screening in this rare disorder.
Conclusion. Early detection and objective assessment of OSAS should be considered an important component of comprehensive care for children with Hunter syndrome. In the presence of marked snoring, disturbed sleep, or signs of upper-airway obstruction, timely overnight cardiorespiratory monitoring or polysomnography is warranted.
Keywords: Hunter syndrome; mucopolysaccharidosis type II; obstructive sleep apnoea syndrome; polysomnography; children.
