46 Xy Disorder Of Sex Development Due To Isolated 17 20 Lyase Deficiency C5681470
A rare condition involving deficiency of the 17,20-lyase enzyme needed for androgen synthesis. Affects 46,XY individuals and causes undervirilization. Managed with hormone therapy.
Key facts at a glance
- ICD-10
- N50.9
- ICD-11
- GA00.0
- Body system
- reproductive
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Hypertension
Elevated blood pressure resulting from accumulation of mineralocorticoids due to blocked sex steroid production pathway.
Seek immediate care if blood pressure reading exceeds 180/120 mmHg or with symptoms like severe headache or chest pain.
Ambiguous genitalia
(reproductive)External genitalia that are neither clearly male nor clearly female, resulting from inadequate androgen production during fetal development.
Frequency: 90-100% of patients
Primary amenorrhea
(reproductive)Absence of menstruation by age 15 or within 3 years of breast development, due to lack of estrogen production.
Frequency: 90-100% of patients
Absence of puberty
(reproductive)Lack of development of secondary sexual characteristics including breast development, menstrual cycles, and body hair growth.
Frequency: 90-100% of patients
Underdeveloped breasts
(reproductive)Minimal or absent breast development due to insufficient estrogen production from the ovaries.
Frequency: 85-95% of patients
Infertility
(reproductive)Inability to conceive naturally due to lack of ovarian function and sex hormone production.
Frequency: 80-90% of patients
Sparse pubic hair
(reproductive)Limited or absent development of pubic hair due to androgen deficiency.
Frequency: 70-80% of patients
Absent or underdeveloped uterus
(reproductive)Underdevelopment or absence of the uterus due to hormonal factors affecting Müllerian duct development.
Frequency: 60-70% of patients
Fatigue
(constitutional)Persistent tiredness and lack of energy due to hormonal imbalances affecting metabolism and bodily functions.
Frequency: 30-40% of patients
Short stature
(reproductive)Frequency: 20-30% of patients
Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Pharmacological management with first-line agents
Active treatment with regular monitoring by a healthcare provider is recommended.
Testosterone Hormone Replacement
Physiological testosterone replacement to achieve virilization and maintain male secondary sexual characteristics. Treatment protocols adapted to patient age and developmental stage.
Glucocorticoid Supplementation
If adrenal androgen pathway is also affected, low-dose glucocorticoid replacement may be necessary to maintain cortisol levels and prevent adrenal insufficiency.
Additional treatment options
Gonadectomy and Gender-Affirming Surgery
Surgical removal of intra-abdominal gonads and subsequent gender-affirming procedures if female sex of rearing is chosen. Includes vaginoplasty when indicated.
surgicalGender Identity Support Services
Specialized psychological support addressing DSD-specific challenges including gender assignment decisions, disclosure decisions, and identity exploration throughout development.
psychologicalSteroidogenic Pathway Monitoring
Comprehensive hormone profiling including adrenal and gonadal steroids to assess enzymatic function and treatment adequacy over time.
monitoringWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is 46 Xy Disorder Of Sex Development Due To Isolated 17 20 Lyase Deficiency C5681470?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Miller WL, Auchus RJ. The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders. Endocr Rev. 2011;32(1):81-151.
Melmed S, Auchus RJ, Abir A, et al. Williams Textbook of Endocrinology. 14th ed. Elsevier; 2020.
Mendonca BB, Batista RL, Domenice S, et al. Steroidogenic disorders: a comprehensive review of 46,XY DSD due to steroid enzyme defects. Endocr Rev. 2023;44(2):261-332.
Lee PA, Houk CP, Ahmed SF, Hughes IA. Consensus statement on management of intersex disorders. International Consensus Conference on Intersex. Pediatrics. 2006;118(2):e488-e500.
Endocrine Society. Clinical practice guideline: management of congenital adrenal hyperplasia. J Clin Endocrinol Metab. 2018;103(11):4043-4083.
Ahmed SF, Bashamboo A, Lucas-Herald A, McGowan R. Understanding the genetic basis of 46,XY disorders of sex development. Endocr Dev. 2014;27:123-135.
Rosa S, Duff C, Meyer M, et al. Clinical phenotype and molecular characterization of five patients with 17,20-lyase deficiency. J Clin Endocrinol Metab. 2020;105(5):dgz045.
Gomes LG, Madureira G, Mendonca BB, et al. Systematic review of steroidogenesis defects in 46,XY DSD: genotype-phenotype correlations. Nat Rev Endocrinol. 2021;17(8):483-498.
Online Mendelian Inheritance in Man (OMIM). CYP17A1 gene - 17-alpha-hydroxylase/17,20-lyase deficiency. OMIM Entry #202300.
Hughes IA, Nihoyannopoulos P, Smith AD, et al. British Society for Paediatric Endocrinology and Diabetes (BSPED) Consensus Statement on 46,XY DSD. Arch Dis Child. 2021;106(7):659-668.
Medication Comparisons
Compare medications used to treat 46 Xy Disorder Of Sex Development Due To Isolated 17 20 Lyase Deficiency C5681470. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy