The deficiency causes the virilization of XX fetuses. The onset of the symptoms usually displayed during adolescent or early adulthood. The lack of estrogen results in the presentation of primary amenorrhea and tall stature. The taller than expected height occurs because estrogen normally causes fusion of the epiphyseal growth plates in the bones, and in its absence, the patient will keep growing longer. The gonadotropins LH and FSH will both be elevated and patients present with polycystic ovaries. Furthermore, the low oestrogen will predispose those with the condition to osteoporosis. Female * After birth, female infant usually displays ambiguous genitalia including labioscrotal fusion, clitoromegaly, and phallic-structure genitalia. Hyperandrogenism is present at birth along with low level of estrogen in the blood. However, they have normal internal female genitalia. Other presented symptoms assist with the correct diagnostics. * During pubertal age, progressive sign of virilisation such as growing of body hair can be observed along with puberty failure due to the lack of estradiol action. The disruption of the LHRH-LH/FSH axis causes bone age to delay with the absence of growth spurt. * In adulthood, symptoms include virilisation, absent of breast development, primary amenorrhea and infertility, and multicystic ovaries. * Other symptoms include hypergonadotropic hypogonadism, polycystic ovaries, hypoplastic ovaries and tall stature. Male Symptoms are generally manifested in adulthood: * Tall stature, osteopenia, osteoporosis, Type II Diabetes, hyperinsulinemia, acanthusis nigricans, lipid metabolism disorders and liver function impairment. During pregnancy During gestation, a baby with<unk>  can cause a mother to become virilised by causing the deepening of the voice, cystic acne, more hair growth than normal, cliteromegaly, and hirsutism. The mother also has an increased level of circulating testosterone. However, the symptoms normally regress post-partum. Comorbidity<unk>  may be comorbid with Autism through their mutual relationship with RORA deficiency. This affects both males and females however the effect on males is more common due to the female protective effect. RORA is the gene for aromatase, an enzyme that converts male to female hormones. Thus, RORA deficiency is linked to<unk> , which in turn can lead to elevated testosterone levels, a proposed risk factor for autism. Complications Pregnant mother Aromatase is an estrogen synthase that synthesize estrone (E1) and estradiol (E2) from Androstenedione and Testosterone respectively. During pregnancy, the placenta, which is fetal tissue, synthesizes large amounts of the intermediates in the biosynthesis of the estrogens, androstenedione and testosterone, but cannot convert them to estrogens due to the absence of aromatase. The levels of accumulated androgens in the mother can elevate 100-fold higher than normal cycling levels which subsequently virilise both the mother and the fetus. The mother will experience cystic acne, deepening of the voice and hirsutism. However, these symptoms are normally resolved following parturition. If the fetus is a male, it will develop a normal male genitalia and will proceed to grow normally and exhibit secondary male sex characteristics. If the fetus is a female, it will be born with ambiguous genitalia including labioscrotal fusion and a greatly enlarged phallus. Female Aromatase deficient female cannot synthesize estrone or estradiol in the absence of aromatase. The amount of androgen will accumulate at a very high rate in the blood, disrupting the LHRH-LH/FSH axis that can potentially lead to polycystic ovaries in adulthood. In the absence of estrogen, high level of circulating LH and FSH can results in Hypergonadotropic hypogonadism. While females begin to virilise and grow hair in various places during adolescent, they are unable to menstruate without the presence of estradiol, subsequently causing primary amenorrhea, clitormegaly, and absence of breast development. As puberty fails, the growth spurt is absence and bone age is delayed. Without treatment, the collection of excessive androgen in the blood can lead to development of polycystic ovaries. Male Aromatase deficient males experience a normal growth into adulthood. With a very low level of circulating estrogen (<7pg/mL), resulting in a higher level of FSH and LH in the blood. Elevated level of androgens do not contribute to harmonic skeletal muscle growth like estrogen, thus, patients exhibits eunuchoid body habitus. Patients are generally tall in stature and have a pattern of persistent linear bone growth into adulthood. Without estrogen, the epiphyseal plates cannot fuse together properly, resulting in continuous height growth. As a necessary steroid to maintain bone homeostasis, low level of estrogen also result osteopenia and osteoporosis of the lumbar spine and cortical bone. Estrogen is also thought to be linked to the abnormal lipid profile and hyperinsulinemia in men, however, the detail mechanism is unknown.
Aromatase deficiency
Estrogen insensitivity syndrome
Isolated 17,20-lyase deficiency
5α-Reductase 2 deficiency
Partial androgen insensitivity syndrome
Androgen-induced hermaphroditism
Congenital estrogen deficiency
Aromatase excess syndrome