XYY syndrome
ICD-10: Q98.5MeSH: D014997ORPHA: 8
Overview
genetic condition in which a male has an extra Y chromosome
Available Treatments (0)
No treatments linked yet
Clinical trials or compassionate use may be available — consult a specialist.
Clinical Presentation
Signs and symptoms associated with XYY syndrome, sourced from HPO and Orphanet clinical annotations.
TicsAbnormal emotional stateObsessive-compulsive traitReduced social responsivenessTall statureMalar flatteningLow-set earsDelayed speech and language developmentMotor delayMacrocephalyHypertelorismAtypical behaviorHyperactivityEnuresisIntellectual disabilityNeonatal hypotoniaSpecific learning disabilityTremorPes planusAsthmaAttention deficit hyperactivity disorderEarly-onset non-progressive night blindnessFinger clinodactylyImpulsivityAzoospermiaCryptorchidismHypospadiasMacroorchidismMicropenisHydrocephalusMandibular prognathiaAutistic behaviorAnxietyOligozoospermiaIncreased circulating gonadotropin levelSeizureMacrodontiaDysgenesis of the cerebellar vermisAbnormal brainstem morphologyMale infertilityCerebellar dysplasiaOppositional defiant disorderVaricoceleIncreased serum testosterone levelEncopresis
Classification & Codes
ICD-10 Code
Q98.5MeSH Code
D014997Orphanet Code
ORPHA:8XYY syndrome
| ICD-10 | Q98.5 |
| MeSH | D014997 |
| Orphanet | ORPHA:8 |
| Treatments | 0 drug(s) |
| Symptoms on record | 45 signs |
| Status | published |
Factual Authority
Last Updated3/20/2026
Clinical DataHPO · Orphanet
Drug DataFDA · EMA · CDSCO