Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is characterized by inappropriately low serum concentrations of the gonadotropins LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in the presence of low circulating concentrations of sex steroids. IGD is associated with a normal sense of smell (normosmic IGD) in approximately 40% of affected individuals and an impaired sense of smell (Kallmann syndrome) in approximately 60%. IGD can first become apparent in infancy, adolescence, or adulthood. Infant boys with congenital IGD often have micropenis and cryptorchidism. Adolescents and adults with IGD have clinical evidence of hypogonadism and incomplete sexual maturation on physical examination. Adult males with IGD tend to have prepubertal testicular volume (i.e., <4 mL), absence of secondary sexual features (e.g., facial and axillary hair growth, deepening of the voice), decreased muscle mass, diminished libido, erectile dysfunction, and infertility. Adult females have little or no breast development and primary amenorrhea. Although skeletal maturation is delayed, the rate of linear growth is usually normal except for the absence of a distinct pubertal growth spurt.

CTDP1-related congenital cataracts, facial dysmorphism, and neuropathy (CTDP1-CCFDN) is characterized by abnormalities of the eye (bilateral congenital cataracts, microcornea, microphthalmia, micropupils), mildly dysmorphic facial features apparent in late childhood, and a hypo-/demyelinating, symmetric, distal peripheral neuropathy. The neuropathy is predominantly motor at the onset and results in delays in early motor development, progressing to severe disability by the third decade of life. Secondary foot deformities and scoliosis are common. Sensory neuropathy develops after age ten years. Most affected individuals have a mild nonprogressive intellectual deficit and cerebellar involvement including ataxia, nystagmus, intention tremor, and dysmetria. All have short stature and most have subnormal weight. Adults have hypogonadotropic hypogonadism. Parainfectious rhabdomyolysis (profound muscle weakness, myoglobinuria, and excessively elevated serum concentration of creatine kinase usually following a viral infection) is a potentially life-threatening complication. To date all affected individuals and carriers identified have been from the Romani population.

Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is characterized by inappropriately low serum concentrations of the gonadotropins LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in the presence of low circulating concentrations of sex steroids. IGD is associated with a normal sense of smell (normosmic IGD) in approximately 40% of affected individuals and an impaired sense of smell (Kallmann syndrome) in approximately 60%. IGD can first become apparent in infancy, adolescence, or adulthood. Infant boys with congenital IGD often have micropenis and cryptorchidism. Adolescents and adults with IGD have clinical evidence of hypogonadism and incomplete sexual maturation on physical examination. Adult males with IGD tend to have prepubertal testicular volume (i.e., <4 mL), absence of secondary sexual features (e.g., facial and axillary hair growth, deepening of the voice), decreased muscle mass, diminished libido, erectile dysfunction, and infertility. Adult females have little or no breast development and primary amenorrhea. Although skeletal maturation is delayed, the rate of linear growth is usually normal except for the absence of a distinct pubertal growth spurt.

Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is characterized by inappropriately low serum concentrations of the gonadotropins LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in the presence of low circulating concentrations of sex steroids. IGD is associated with a normal sense of smell (normosmic IGD) in approximately 40% of affected individuals and an impaired sense of smell (Kallmann syndrome) in approximately 60%. IGD can first become apparent in infancy, adolescence, or adulthood. Infant boys with congenital IGD often have micropenis and cryptorchidism. Adolescents and adults with IGD have clinical evidence of hypogonadism and incomplete sexual maturation on physical examination. Adult males with IGD tend to have prepubertal testicular volume (i.e., <4 mL), absence of secondary sexual features (e.g., facial and axillary hair growth, deepening of the voice), decreased muscle mass, diminished libido, erectile dysfunction, and infertility. Adult females have little or no breast development and primary amenorrhea. Although skeletal maturation is delayed, the rate of linear growth is usually normal except for the absence of a distinct pubertal growth spurt.

Perrault syndrome is characterized by sensorineural hearing loss (SNHL) in males and females and ovarian dysfunction in females. SNHL is bilateral and ranges from profound with prelingual (congenital) onset to moderate with early-childhood onset. When onset is in early childhood, hearing loss can be progressive. Ovarian dysfunction ranges from gonadal dysgenesis (absent or streak gonads) manifesting as primary amenorrhea to primary ovarian insufficiency (POI) defined as cessation of menses before age 40 years. Fertility in affected males is reported as normal (although the number of reported males is limited). Neurologic features described in some individuals with Perrault syndrome include learning difficulties and developmental delay, cerebellar ataxia, and motor and sensory peripheral neuropathy.

Premature ovarian failure (POF), the endpoint of primary ovarian insufficiency, affects approximately 1% of women worldwide. Patients with POF present with at least a 6-month history of amenorrhea and elevated plasma levels of follicle-stimulating hormone (more than 40 mIU per milliliter). The disorder can result from premature depletion of the follicle pool, follicular atresia, follicle growth arrest, or ovarian dysgenesis (see 233300). In approximately 10 to 15% of patients with POF, a genetic cause has been determined (summary by Caburet et al., 2014). For general phenotypic information and a discussion of genetic heterogeneity of premature ovarian failure, see POF1 (311360).

Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is characterized by inappropriately low serum concentrations of the gonadotropins LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in the presence of low circulating concentrations of sex steroids. IGD is associated with a normal sense of smell (normosmic IGD) in approximately 40% of affected individuals and an impaired sense of smell (Kallmann syndrome) in approximately 60%. IGD can first become apparent in infancy, adolescence, or adulthood. Infant boys with congenital IGD often have micropenis and cryptorchidism. Adolescents and adults with IGD have clinical evidence of hypogonadism and incomplete sexual maturation on physical examination. Adult males with IGD tend to have prepubertal testicular volume (i.e., <4 mL), absence of secondary sexual features (e.g., facial and axillary hair growth, deepening of the voice), decreased muscle mass, diminished libido, erectile dysfunction, and infertility. Adult females have little or no breast development and primary amenorrhea. Although skeletal maturation is delayed, the rate of linear growth is usually normal except for the absence of a distinct pubertal growth spurt.

A rare genetic disorder of sex development characterized by primary amenorrhea, short stature, delayed bone age, decreased levels of estradiol, elevated levels of follicle-stimulating hormone and luteinizing hormone, absent or underdeveloped uterus and ovaries, delayed development of pubic and axillary hair and normal 46,XX karyotype.

Premature ovarian failure-14 (POF14) is characterized by amenorrhea, hypoestrogenism, and elevated gonadotropin levels (Franca et al., 2018). For a general phenotypic description and discussion of genetic heterogeneity of premature ovarian failure, see POF1 (311360).

Ovarian dysgenesis-7 (ODG7) is characterized by primary amenorrhea, delayed puberty, elevated gonadotropic hormones, and small uterus and ovaries. Ovarian histology shows fibrotic ovaries without follicles (Chen et al., 2018). For a discussion of genetic heterogeneity of ovarian dysgenesis, see ODG1 (233300).

Ovarian dysgenesis-8 (ODG8) is characterized by complete lack of estrogen action, resulting in absent breast development, primary amenorrhea, and osteoporosis (Lang-Muritano et al., 2018). For a discussion of genetic heterogeneity of ovarian dysgenesis, see ODG1 (233300).

Premature ovarian failure-16 (POF16) is characterized by onset of amenorrhea early in the fourth decade of life, accompanied by elevated follicle-stimulating hormone (FSH; see 136530) levels and low estradiol levels. Ovaries are smaller than normal and show a solid echo pattern with no antral follicle (Zhang et al., 2018).

Hypogonadotropic hypogonadism-25 with anosmia (HH25) is characterized by delayed or absent puberty with low gonadotropic hormones in the setting of low testosterone or estradiol. Affected individuals also exhibit hyposmia or anosmia, with hypoplastic olfactory bulbs on MRI. Intrafamilial variable expressivity and incomplete penetrance has been observed (Messina et al., 2020). For a discussion of genetic heterogeneity of hypogonadotropic hypogonadism with or without anosmia, see 147950.

Premature ovarian failure-17 (POF17) is characterized by early cessation of menses after initial menarche, with small ovaries and uterus (Zhang et al., 2019). For a discussion of genetic heterogeneity of premature ovarian failure, see POF1 (311360).

Ovarian dysgenesis-9 (ODG9) is characterized by severe nonsyndromic primary ovarian insufficiency with primary amenorrhea, hypoplastic or absent ovaries, and delayed bone age. Patient cells show evidence of chromosomal instability (Smirin-Yosef et al., 2017; Heddar et al., 2022). For a general phenotypic description and discussion of genetic heterogeneity of ovarian dysgenesis, see ODG1 (233300).

Ovarian dysgenesis-10 (ODG10) is characterized by primary amenorrhea and absent puberty. The uterus is small and prepubertal, and ovaries are streak or not visualized on ultrasound (McGlacken-Byrne et al., 2022). Mutation in the ZSWIM7 gene also causes male infertility due to spermatogenic failure (SPGF71; 619831). For a general phenotypic description and discussion of genetic heterogeneity of ovarian dysgenesis, see ODG1 (233300).

Premature ovarian failure-21 (POF21) is characterized by female infertility due to primary or secondary amenorrhea. Ovaries are small, atrophic, or nonvisualized on ultrasound (Tucker et al., 2019; Tucker et al., 2022). For a general phenotypic description and a discussion of genetic heterogeneity of POF, see POF1 (311360).