Eunuchoidism Familial Hypogonadotropic

Familial hypogonadotropic eunuchoidism is a rare congenital endocrine disorder in which normal development of the genital organs and secondary sexual characteristics is disrupted due to insufficient production of gonadotropin-releasing hormone (GnRH) by the hypothalamus. This leads to suppression of the secretion of follicle-stimulating (FSH) and luteinizing (LH) hormones by the pituitary gland, resulting in hypogonadism with low testosterone levels in men or estrogens in women. Unlike other forms of hypogonadism, the gonadal tissue itself remains structurally intact and potentially functional — the problem lies "higher up," in central regulation. In men, this manifests as delayed puberty, tall stature with "long-nosed" proportions, lack of male-pattern hair growth, small testicles, a poorly developed voice, and consequently, infertility. In women — primary amenorrhea, absence of mammary glands, virgin form of external genitalia. At the same time, intelligence and psycho-emotional development are usually unaffected. It is important to understand: this is not a "weakness of character" or a result of trauma — it is a genetically determined pathology that requires precise diagnosis and timely treatment.

Classification of the disease according to ICD-10 and ICD-11

In the International Classification of Diseases, 10th revision (ICD-10), familial hypogonadotropic eunuchoidism falls under the category E29.1 — Hypogonadotropic hypogonadism, subcategory "congenital." In the more modern version — ICD-11 (introduced in Russia in 2022) — it is coded as 5A73.0 — Congenital hypogonadotropic hypogonadism, with the specification "with impaired GnRH secretion." The key difference between ICD-10 and ICD-11 is the emphasis on the pathogenetic mechanism: while previously the focus was on the clinical phenomenon (hypogonadism), now forms are clearly differentiated by origin — hypothalamic, pituitary, peripheral.
Important: ICD-11 also distinguishes subtypes:

• 5A73.00 — with anosmia (Kallmann syndrome);
• 5A73.01 — without anosmia (isolated hypogonadotropic hypogonadism);
• 5A73.02 — with additional anomalies (for example, developmental defects of the kidneys, heart, skeleton).

This allows the doctor not only to make a diagnosis but also to immediately focus on genetic testing and prognosis. For example, in the presence of anosmia, the chance of detecting a mutation in the gene ANOS1 (formerly KAL1) increases to 60% in men. And if there is no anosmia, mutations are most often sought in GNRHR, PROKR2, FGFR1 or CHD7. Such detailing directly affects the tactics of monitoring and counseling the family.

History of the disease and interesting historical facts

The first descriptions of a condition resembling eunuchoidism can be found in ancient Greek texts. Hippocrates mentioned "young men who do not reach maturity," and Galen suggested that the cause might be "a lack of heat in the testicles." But a real breakthrough occurred in the 19th century when surgeons began to systematically describe cases after castration — and noticed that those who were castrated in childhood developed exactly such a phenotype: tall stature, long limbs, absence of beard, feminine body structure. Hence the name "eunuchoidism" — from Greek *eunouchos* — "keeper of the bedroom," that is, eunuch.
However, a key turning point occurred in 1944 when American endocrinologist **Maurice Black** described a case of a young man with amenorrhea, absence of smell, and hypogonadism — later this became known as Kallmann syndrome (named after the German scientist Franz Kallmann, who published a detailed description in 1944–1954). Interestingly, in the Middle Ages, eunuchs often held high positions in the imperial courts of China, Byzantium, and the Ottoman Empire — not due to "weakness," but because of a stable emotional background, absence of sexual conflicts, and, as modern studies show, a longer lifespan compared to non-castrated men of the same social class.
From the perspective of medical ethics, today the term "eunuchoidism" is used exclusively in a clinical context — as a description of the phenotype, not as a stigma. Modern endocrinology tries to avoid stigmatizing language and speaks of "hypogonadotropic hypogonadism with eunuchoid phenotype."

Epidemiology: how common is the disease?

The exact frequency of congenital hypogonadotropic hypogonadism (CHH) has not yet been established due to its rarity and underdiagnosis. According to a meta-analysis from 2021 (Journal of Endocrinology, vol. 250), the average prevalence is **1 case per 10,000–40,000 newborns**, with males affected 5 times more often than females. This is because parents are more likely to seek medical help for girls in the absence of menarche, while in boys, delayed puberty may be attributed to "late maturation" until 18–20 years.
In Russia, the figures are slightly higher: according to statistics from the T.D. Nadezhdina Research Institute of Endocrinology (2023), there are about 12–15 registered cases of CHH per 1 million population. However, the actual number is likely higher — especially in regions with limited access to endocrinological care. For example, in one study in Siberia (Novosibirsk, 2020), it was found that almost 30% of patients suspected of hypogonadism received an incorrect diagnosis for 3–5 years.
Importantly, the disease does not have a pronounced geographical or ethnic attachment. The exception is populations with a high proportion of marriages between relatives (for example, in some mountainous areas of the Caucasus or Central Asia), where the risk of recessive forms (for example, mutations in GNRHR) increases by 10–15 times.

Genetic predisposition: which genes are "guilty"?

CHH is not a single disease but a group of genetic syndromes with a common phenotype. To date, more than 40 genes have been identified, mutations in which can lead to disruption of GnRH secretion or action. They are divided into two large groups:

• Genes responsible for the migration of GnRH neurons. — for example, ANOS1 (X-linked, more often in men), FGFR1, PROKR2, CHD7. Mutations here are often accompanied by anosmia and/or other congenital anomalies (defects of the kidneys, heart, skeleton).
• Genes that disrupt the function of the GnRH receptor or signaling cascade — for example, GNRHR (recessive form, often without anosmia), KISS1R, TAC3/TACR3. These forms are more often isolated, without accompanying defects.

Here is a table of the most significant genes and their features:

If a mutation is detected in one of these genes in the patient — it not only confirms the diagnosis but also allows for genetic counseling for relatives. For example, with a mutation in GNRHR the risk of transmission to children is 25 % when two carriers marry, whereas with ANOS1 — 50 % for sons if the mother is a carrier.

Risk factors: what can provoke or exacerbate the disease?

Although VGG is a congenital condition, its manifestations can be modulated by external factors. Here are the main risk groups:

• Genetic: the presence of cases of delayed puberty, infertility, anosmia, or congenital anomalies in the family. A particularly alarming signal is if an uncle on the maternal side showed signs of eunuchoidism.
• Perinatal: fetal hypoxia, premature birth, intrauterine infections (cytomegalovirus, toxoplasmosis) — can damage the developing hypothalamus, even in the absence of genetic predisposition.
• Exogenous chemical factors: prolonged use of glucocorticoids in childhood (for example, for asthma), anabolic steroids, some antitumor drugs — can temporarily suppress the hypothalamic-pituitary-gonadal axis.
• Psychosocial: chronic stress, sleep deprivation, extreme weight deficiency (for example, in anorexia) — can mask or exacerbate symptoms, especially during adolescence.

Important: in adult men with VGG receiving replacement therapy, abrupt cessation of treatment (for example, due to financial difficulties) can lead to the regression of secondary sexual characteristics — up to testicular atrophy and decreased libido within 3–6 months. This is not a "relapse," but a consequence of the withdrawal of supportive therapy.

Diagnosis: how to recognize VGG and distinguish it from other conditions
The diagnosis is made comprehensively — based on history, physical examination, laboratory, and instrumental data. A key point: **do not confuse with hypogonadotropic hypogonadism of acquired origin** (for example, due to a pituitary tumor or hemochromatosis).
Main symptoms in men:

• Absence of male-pattern hair growth by age 16;
• Testes less than 4 ml (usually 1–2 ml);
• Height > 185 cm with arm span > height;
• Voice has not deepened — retains a childlike tone;
• Absence of spermatogenesis (azoospermia).

In women:

• Absence of menarche by age 16;
• Absence of breast development;
• Virgin form of the vagina;
• Low estradiol level (< 20 pg/ml).

Laboratory tests are mandatory:

• Blood hormones: low testosterone (< 100 ng/dl in men), low LH and FSH (often < 1.5 IU/l), normal or decreased AFP and hCG (to rule out tumor).
• Stimulation tests: administration of GnRH (100 mcg IV) — in HH the response of LH/FSH is weak or absent; in hypogonadism due to pituitary insufficiency — the response may be partial.
• Genetic testing: panel of 30+ genes (NGS sequencing) — standard for confirming diagnosis and choosing tactics.

Radiological methods:

• MRI of the brain with contrast — to rule out pituitary tumor, cyst, agenesis of the olfactory bulbs (in case of anosmia).
• Pelvic ultrasound in women — to assess the size of the uterus and ovaries (in HH they are hypoplastic, but the structure is preserved).

Differential diagnosis includes:

• Isolated hypogonadotropic hypogonadism of acquired type (tumor, trauma, hemochromatosis);
• Hypergonadotropic hypogonadism (Klinefelter syndrome, Turner syndrome);
• Marfan syndrome or other connective tissue dysplasias (tall stature but with normal sexual development);
• Psychogenic delay of puberty (more often in girls, with normal hormones and rapid response to stress factors).

Treatment: how to restore hormonal balance and quality of life?

Treatment of HGG is not "cure," but correction of the consequences of a genetic defect. The goal: to achieve physiological puberty, preserve fertility (if possible), prevent osteoporosis, and improve psychological adaptation. Tactics depend on age, gender, desire to have children, and the presence of accompanying anomalies.
In adolescents (14–16 years) they start with low doses of testosterone (in boys) or estrogens (in girls), gradually increasing to physiological levels. For example:

• Testosterone in men: initial dose 50 mg/week in the form of depot injections (testosterone enanthate), then switching to gels or patches.
• Estrogens in women: estradiol valerate 1–2 mg/day orally, with the addition of progesterone after 12 months for cyclic protection of the endometrium.

This stage is called induction of puberty. It lasts 2–3 years and should be conducted under the supervision of an endocrinologist — to avoid premature closure of growth zones (epiphyseal cartilages). If started too early — growth will stop at 160–165 cm, if too late — the patient may remain with an "eunuchoid" physique.
In adults the task is to maintain hormonal background lifelong. Here, more effective schemes can be applied:

• Testosterone replacement therapy — for men: gels (1% solution), injections every 2 weeks, subcutaneous implants. Effectiveness: increase in muscle mass, improvement in libido, mood, bone density.
• Stimulation of spermatogenesis — for those wishing to have children: combination of chorionic gonadotropin (hCG) + FSH (for example, menotropins). Course 12–24 months, success — in 60–70 % cases with isolated form without mutations in GNRHR.
• GnRH pulsator — a device that mimics the natural pulse of the hormone (once every 90–120 min). Used rarely — only in specialized centers (for example, at the Research Institute of Endocrinology in Moscow), but provides the most physiological response: restoration of spermatogenesis and cyclic ovulation in women.

Surgical treatment is not required — except in rare cases where there are associated anomalies (for example, cryptorchidism requiring orchidopexy in childhood). The main thing is to avoid self-treatment: taking "anabolics" without hormone control leads to testicular atrophy and irreversible infertility.

List of medications used in HG

Here are the main medications registered in the Russian Federation and used in clinical practice:

Note: drugs like "clomiphene" or "anastrozole" are **ineffective** in HGG — they only work with a functioning pituitary gland. Their use without a confirmed diagnosis is a common mistake that leads to a loss of time and money.

Monitoring, prognosis, and possible complications

Patients with HGG require lifelong monitoring. Minimum control schedule:

• Every 3 months in the first 2 years of treatment: testosterone/estradiol levels, LH, FSH, hematocrit, PSA (in men over 40), ultrasound of the testes/uterus.
• Every 6 months after stabilization: bone densitometry (DEXA), ECG, urine protein analysis (in the presence of concomitant anomalies).
• Annually: examination by an endocrinologist, assessment of psychological state, counseling on reproductive issues.

The prognosis with timely treatment is favorable:

• Physical development corresponds to age;
• Quality of life is not different from healthy peers;
• Fertility is achievable in 60–80% of cases in the isolated form;
• Life expectancy is normal if therapy regimen is followed.

Complications arise from ignoring treatment or incorrect tactics:

• Osteoporosis — by age 30, bone density may decrease by 20–30%, the risk of fractures increases 5 times;
• Anemia — due to testosterone deficiency (it stimulates erythropoiesis);
• Depression and social isolation** — especially in adolescents who have not undergone puberty induction;
• Metabolic disorders** — increased risk of insulin resistance and fatty liver with prolonged deficiency of sex hormones.

Key point: even with successful stimulation of spermatogenesis, men with mutations in GNRHR or TAC3 sperm may be oligoasthenoteratozoospermic — therefore, ICSI (intracytoplasmic sperm injection) is recommended before IVF.

Age-related features: how does HG manifest in children, adolescents, and adults?

In newborns, HHG is practically not manifested — except for rare cases when there are associated anomalies (for example, micropenis, cryptorchidism, renal agenesis). The diagnosis at this age is made only with genetic screening or if there is already a confirmed case in the family.
In the period of 6–12 years — the first "bells" appear:

• In boys — absence of testicular enlargement by age 10 (normal — ≥ 4 ml);
• In girls — absence of thelarche (breast development) by age 8;
• Height exceeds the norm by 1.5–2 SD, but proportions are "long-nosed" (leg length > torso length).

The adolescent period (13–18 years) is critical. It is here that the fate of the phenotype is determined. If therapy is not started before age 15 — the risk of irreversible eunuchoid constitution is high. But starting too early (before age 12) is also dangerous: it can lead to premature closure of the epiphyses and short stature.
In adults (19–40 years), the focus shifts to:

• Restoration of fertility;
• Prevention of osteoporosis;
• Psychosocial adaptation (work, relationships, self-esteem).

After age 40, it is important to monitor:

• Cardiovascular risk (testosterone protects against atherosclerosis);
• Metabolic syndrome;
• Cognitive functions — deficiency of sex hormones is associated with accelerated memory decline.

Interesting fact: men with HHG who receive therapy from youth have cognitive test scores (especially spatial thinking) that do not lag behind the control group — which refutes the myth of the "inferiority" of such patients.

Questions and answers: the most frequent patient inquiries

1. Question 1: Is it possible to completely cure eunuchoidism? Or is it a lifelong condition?**
2. Answer: There is no complete "cure" like with an infection — the genetic defect remains. But with the help of replacement therapy, it is possible to achieve physiological levels of sex hormones, normal sexual development, and, in most cases, fertility. It is not a disease, but a chronic condition that is successfully managed — like diabetes or hypothyroidism. The main thing is not to stop treatment and to have regular check-ups.
3. Question 2: If I have HH, can I become a father?**
4. Answer: Yes, in 60–80% of cases — provided that the form is isolated and there are no mutations in the genes that block spermatogenesis (for example, with zero activity). Scheme: hCG + FSH for 12–24 months, then sperm collection for ICSI. In the Endocrinology Research Institute over the last 5 years, 47 men with HH have become fathers. The key factor is to start stimulation before the age of 30, while the seminiferous tubules have not atrophied. GNRHR 5. Question 3: Why do I have a normal sense of smell, but the diagnosis is Kallmann syndrome?**
6. Answer: This is a common confusion. Kallmann syndrome is a subtype of HH with anosmia. If the sense of smell is preserved, the diagnosis is —
7. isolated hypogonadotropic hypogonadism. 8. Sometimes the history indicates "reduced sense of smell," but upon objective testing (for example, using an odor panel), it turns out to be within normal limits. Genetic testing will help clarify: mutations in9. almost always come with anosmia, while in ANOS1 10. — without it. GNRHR 11. Question 4: Can I take "anabolics" from the gym instead of testosterone?**
12. Answer: Absolutely not. Anabolic steroids (for example, methandrostenolone) suppress the body's own GnRH production even more, cause testicular atrophy, and increase the risk of prostate cancer and cardiovascular disasters. Replacement therapy must be strictly dosed, under hormone control and ultrasound. Cheap "sports supplements" are not treatment, but a threat to health.
13. Question 5: How should I prepare for the first consultation with an endocrinologist?**
14. Answer: Bring with you:
15. Data on height and weight from birth (preferably graphs);

1. "I'll wait until 18 — maybe it will happen on its own"**
— Incorrect. After 16, the chance of spontaneous onset of puberty in HH is close to zero. Each year of delay results in a loss of 2–3 cm in height and worsens fertility prognosis.
2. Self-prescribing clomiphene or tamoxifen**
— These medications only work in hypergonadotropic hypogonadism (for example, in Klinefelter syndrome). They are ineffective in HH and can cause side effects (headaches, vision disturbances).
3. Stopping therapy upon "feeling better"**
— Testosterone is not an analgesic. Its discontinuation leads to the regression of all acquired signs: decreased muscle mass, worsened mood, osteoporosis. Lifelong treatment is not a deficiency but a feature of the pathology.
4. Ignoring genetic counseling**
— If you have HH, your children have a 25–50% risk. Knowing the gene allows for prenatal diagnosis or PGD during IVF. It's not worth "hoping for the best" — it's a responsibility to future generations.
5. Searching for information only on social media and forums**
— There are many myths: "HH is treated with iodine," "you can restore the testicles with folk remedies." Trust only verified sources: the website of the Endocrinology Research Institute, REN, clinical guidelines from the Ministry of Health.

If you are faced with the task of understanding the diagnosis, choosing therapy, or simply understanding what is happening with your body — remember: you have the right to accurate information, respect, and quality help. As a doctor with 20 years of experience, I see daily how patients with HGG become successful specialists, fathers, husbands, and mothers. The main thing is not to isolate yourself, not to believe in myths, and to seek a specialist. Your story is not yet written — and it can be wonderful.