Aromatase deficiency caused by mutation of CYP19A1 gene: A case report. / CYP19A1åŸºå› çªå˜è‡´èŠ³é¦™åŒ–é ¶ç¼ºä¹ç—‡1例.

Aromatase deficiency (AD) is a rare autosomal recessive genetic disease caused by loss-of-function mutations in aromatase gene (CYP19A1), leading to congenital estrogen deficiency syndrome. Both mothers of AD patients during pregnancy and female AD fetus show virilization, while male patients are usually diagnosed in adulthood due to continued height increase and metabolic abnormalities. In 2019, a patient with AD was admitted in the Second Xiangya Hospital. The patient was a 37-year-old adult male who continued to grow linearly after adulthood. His estradiol was below the measurable line, the follicle-stimulating hormone (FSH) increased, bone age delayed, epiphysis unfused, and the bone mass reduced. CYP19A1 gene detection showed that c.1093C>T, p.R365W was homozygous mutation. This disease is rare in clinic. Clinicians need to raise awareness of the disease for early diagnosis and treatment to improve the long-term prognosis of patients.

Aromatase deficiency: A case series of 46, XX Chinese children and a systematic review of the literature.

BACKGROUND: Aromatase deficiency (AD) caused by cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1) variants is characterized by a deficiency in androgen-to-oestrogen conversion. OBJECTIVE: To investigate the clinical characteristics and accurate management of aromatase-deficient children. PATIENTS AND METHODS: We described three 46, XX aromatase-deficient children, searched PubMed with "(aromatase deficiency) AND (46, XX OR ovaries)" and manually searched citations in identified studies for the literature review. RESULTS: Two girls and one boy (3.4-9.2 years) with the 46, XX karyotype presented ambiguous genitalia and maternal antenatal virilization, normal-low height, delayed bone age, normal glucose and lipid profiles, markedly elevated follicle-stimulating hormone (FSH) levels and poor oestradiol responses to human menopausal gonadotropin stimulation. Ultrasound revealed normal-sized uterus and ovaries with undetectable follicles. Histopathology revealed primordial follicles and few primary follicles in ovaries. One patient presented granulosa and follicular membrane cell proliferation and interstitial sclerosis. We identified four CYP19A1 variants; c.146_158del and c.344G >A were unreported. We reviewed available data from thirty 46, XX patients (0.2-32 years). Some patients were not diagnosed until puberty/adulthood; three were initially misdiagnosed with congenital adrenocortical hyperplasia. The main characteristics were maternal antenatal virilization (21/29), ambiguous genitalia (mainly Prader IV or III, 19/23), delayed bone age (16/17), low bone mass (5/8), markedly elevated FSH levels and ovarian cysts (13/30). CONCLUSIONS: 46, XX AD is easily neglected or misdiagnosed. Ambiguous genitalia, maternal antenatal virilization and markedly elevated FSH levels are important diagnostic indicators. We described two novel variants, new histopathological features of ovaries and an early management strategy.

46,XX DSD due to Androgen Excess in Monogenic Disorders of Steroidogenesis: Genetic, Biochemical, and Clinical Features.

The term 'differences of sex development' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, or anatomical sex. Disorders of steroidogenesis comprise autosomal recessive conditions that affect adrenal and gonadal enzymes and are responsible for some conditions of 46,XX DSD where hyperandrogenism interferes with chromosomal and gonadal sex development. Congenital adrenal hyperplasias (CAHs) are disorders of steroidogenesis that mainly involve the adrenals (21-hydroxylase and 11-hydroxylase deficiencies) and sometimes the gonads (3-beta-hydroxysteroidodehydrogenase and P450-oxidoreductase); in contrast, aromatase deficiency mainly involves the steroidogenetic activity of the gonads. This review describes the main genetic, biochemical, and clinical features that apply to the abovementioned conditions. The activities of the steroidogenetic enzymes are modulated by post-translational modifications and cofactors, particularly electron-donating redox partners. The incidences of the rare forms of CAH vary with ethnicity and geography. The elucidation of the precise roles of these enzymes and cofactors has been significantly facilitated by the identification of the genetic bases of rare disorders of steroidogenesis. Understanding steroidogenesis is important to our comprehension of differences in sexual development and other processes that are related to human reproduction and fertility, particularly those that involve androgen excess as consequence of their impairment.

46,XX aromatase deficiency: A single-center experience with the varied spectrum and recurrent variants, and a systematic review of hormonal parameters.

BACKGROUND: Aromatase deficiency is a rare disorder, with only a few cases reported in India. We describe a single-center experience in western India, with a systematic review of genetically proven 46,XX aromatase deficiency patients to evaluate hormonal parameters. METHODS: Retrospective review of case records, collating phenotypic and genotypic data and molecular modeling. Systematic review of 46,XX aromatase deficiency, analyzing data on gonadotropins, estrogen and androgens. RESULTS: In the seven patients from our center, presentation was frequent in childhood or adolescence (4/7: delayed puberty or hyperandrogenism), with maternal virilization (4/7), predominance of Prader III/IV (5/7), and initial rearing as females (6/7). Three patients had hypoplastic ovaries. One patient had spontaneous regular menses. We report three novel (p.Arg115Pro, p.Arg192Pro, and c.145+1_145+4delins) and two recurrent variants (p.Val370Met, and c.145+1_145+4delins) in western and northern India, respectively. On systematic review (n=43), gonadotropins were elevated (FSH>LH) across ages (except preterm infants), androgens were elevated in about one-third of cases during childhood and puberty, and estradiol was lower than in controls in mini-puberty and puberty. Spontaneous thelarche and streak ovaries were significantly more frequent in patients with non-truncating and truncating variants, respectively. CONCLUSION: We report uncommon presentations with possible founder variants, and highlight hormonal parameters across ages. Serum FSH levels were elevated except in preterms, and can be used as a diagnostic marker.

46,XX Differences of Sex Development outside congenital adrenal hyperplasia: pathogenesis, clinical aspects, puberty, sex hormone replacement therapy and fertility outcomes.

The term 'differences of sex development' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, and/or anatomical sex. DSD in individuals with a 46,XX karyotype can occur due to fetal or postnatal exposure to elevated amount of androgens or maldevelopment of internal genitalia. Clinical phenotype could be quite variable and for this reason these conditions could be diagnosed at birth, in newborns with atypical genitalia, but also even later in life, due to progressive virilization during adolescence, or pubertal delay. Understand the physiological development and the molecular bases of gonadal and adrenal structures is crucial to determine the diagnosis and best management and treatment for these patients. The most common cause of DSD in 46,XX newborns is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, determining primary adrenal insufficiency and androgen excess. In this review we will focus on the other rare causes of 46,XX DSD, outside CAH, summarizing the most relevant data on genetic, clinical aspects, puberty and fertility outcomes of these rare diseases.

Diagnosis and management of non-CAH 46,XX disorders/differences in sex development.

Prenatal-onset androgen excess leads to abnormal sexual development in 46,XX individuals. This androgen excess can be caused endogenously by the adrenals or gonads or by exposure to exogenous androgens. The most common cause of 46,XX disorders/differences in sex development (DSD) is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, comprising >90% of 46,XX DSD cases. Deficiencies of 11ß-hydroxylase, 3ß-hydroxysteroid dehydrogenase, and P450-oxidoreductase (POR) are rare types of CAH, resulting in 46,XX DSD. In all CAH forms, patients have normal ovarian development. The molecular genetic causes of 46,XX DSD, besides CAH, are uncommon. These etiologies include primary glucocorticoid resistance (PGCR) and aromatase deficiency with normal ovarian development. Additionally, 46,XX gonads can differentiate into testes, causing 46,XX testicular (T) DSD or a coexistence of ovarian and testicular tissue, defined as 46,XX ovotesticular (OT)-DSD. PGCR is caused by inactivating variants in NR3C1, resulting in glucocorticoid insensitivity and the signs of mineralocorticoid and androgen excess. Pathogenic variants in the CYP19A1 gene lead to aromatase deficiency, causing androgen excess. Many genes are involved in the mechanisms of gonadal development, and genes associated with 46,XX T/OT-DSD include translocations of the SRY; copy number variants in NR2F2, NR0B1, SOX3, SOX9, SOX10, and FGF9, and sequence variants in NR5A1, NR2F2, RSPO1, SOX9, WNT2B, WNT4, and WT1. Progress in cytogenetic and molecular genetic techniques has significantly improved our understanding of the etiology of non-CAH 46,XX DSD. Nonetheless, uncertainties about gonadal function and gender outcomes may make the management of these conditions challenging. This review explores the intricate landscape of diagnosing and managing these conditions, shedding light on the unique aspects that distinguish them from other types of DSD.

A Novel Homozygous CYP19A1 Gene Mutation Causing Aromatase Deficiency.

Aromatase deficiency is a rare autosomal recessive disorder and its exact prevalence is not known. Aromatase enzyme catalyzes the conversion of androgens to estrogens in gonadal and extra-gonadal tissues. Deficiency of aromatase enzyme can lead to ambiguous genitalia in a female child and maternal virilization during pregnancy due to raised androgen levels in the mother. A 10-month-old child was referred to our outpatient department for the evaluation of ambiguous genitalia. There was a history of maternal virilization during pregnancy. Karyotype of the child was 46XX. Congenital adrenal hyperplasia was ruled out as serum cortisol, plasma adrenocorticotropic hormone, and 17-hydroxyprogesterone were within normal limits. Hormonal assays showed elevated follicle-stimulating hormone and luteinizing hormone, with raised testosterone and low estradiol levels. Based on these findings, aromatase deficiency was suspected. A novel homozygous mutation c.1376delA located on exon 10 was identified on the CYP19A1 gene. We identified a novel mutation in the CYP19A1 gene in a patient who presented with ambiguous genitalia and maternal virilization during pregnancy.

Aromatase deficiency in an Ontario Old Order Mennonite family.

OBJECTIVES: Aromatase deficiency is a rare autosomal recessive disease that results in the absence of aromatase. In females it presents with ambiguous genitalia and lack of secondary sexual characteristics during puberty. Aromatase deficiency is not attributed to any specific population, but it is more commonly seen in consanguineous parents. Herein, we report the first Old Order Mennonite family with that diagnosis. CASE PRESENTATION: Our proband is an Old Order Mennonite female born with ambiguous genitalia who was identified to carry novel homozygous variant in the CYP19A1 gene c.1304G>A (p. Arg435His). Her older brother was later confirmed with the same genetic diagnosis. CONCLUSIONS: Recognizing the cultural sensitivity, unrecognized affected cases, and late presentation of males affected with aromatase deficiency, this condition may be more prevalent than believed in that population.

Aromatase Deficiency in Two Siblings with 46,XX Karyotype Raised as Different Genders: A Novel Mutation (p.R115X) in the CYP19A1 Gene

Aromatase deficiency rarely causes a 46,XX sexual differentiation disorder. The CYP19A1 gene encodes the aromatase enzyme which catalyses the conversion of androgens to oestrogens. In cases with 46,XX karyotype, mutations in the CYP19A1 gene can lead to disorders of sex development. Clinical findings in aromatase deficiency vary depending on the degree of deficiency. The effect of increased androgens, including acne, cliteromegaly and hirsutism, can be observed in mothers with placental aromatase deficiency. A decrease in maternal virilisation symptoms is observable in the postpartum period. It is rarely reported that there is no virilization in pregnancy. In this study, two 46,XX sibling having the p.R115X (c.343 C>T) novel pathogenic variant in the CYP19A1 gene and raised as different genders, with no maternal virilisation during pregnancy, are presented. In conclusion, 46,XX virilised females should be examined in terms of aromatase deficiency once congenital adrenal hyperplasia has been excluded, even if there is no history of maternal virilisation during pregnancy.

Novel CYP19A1 Mutations Extend the Genotype-Phenotype Correlation and Reveal the Impact on Ovarian Function.

CONTEXT: The steroidogenic enzyme aromatase (CYP19A1) is required for estrogen biosynthesis from androgen precursors in the ovary and extragonadal tissues. The role of aromatase, and thus estrogens, is best illustrated by genetic variations of the CYP19A1 gene leading to aromatase deficiency or excess. OBJECTIVE: The objective of this work is to characterize novel CYP19A1 variants. DESIGN SETTING AND PATIENTS: Variants causing aromatase deficiency were suspected in four 46,XX children of African and Indian origin by careful clinical phenotyping. Sequencing of the CYP19A1 gene identified novel variants. Minigene experiments, aromatase activity assay, and computational, and histological analysis were used to characterize the variants. MAIN OUTCOME MEASURE AND RESULTS: CYP19A1 variants were found in all patients: a deletion in intron 9 leading to p.P423_H503del, a delins variant at p.P154, and point variants p.V161D, p.R264C, p.R375C. Except for R264C, all variants showed a loss of function. Protein structure and dynamics studies were in line with functional assays. The 2 female patients with delins variants manifested with ambiguous genitalia at birth. Histologic investigation revealed normal ovarian tissue on one side and a streak gonad on the other. Two female patients presented with abnormal pubertal development and polycystic ovaries. CONCLUSION: In girls, aromatase deficiency usually manifests at birth, but diagnosis may also be made because of abnormal pubertal development or ovarian torsion due to (poly)cystic ovaries. The ovary harboring CYP19A1 variants may present as streak gonad or appears normal at birth, but is then at very high risk to produce cysts with aging and is therefore prone to ovarian torsion.

Maternal exposure to imazalil disrupts the endocrine system in F1 generation mice.

The fungicide imazalil (IMZ), an AR antagonist, has been linked to endocrine disruption in animals. Here, adult female C57BL/6 mice were administered IMZ through their drinking water at levels of 0, 0.025‰ and 0.25‰ during the gestation and lactation periods (the exposed females are marked as F0, and the offspring are marked as F1). Then, we evaluated the physiological, biochemical and gene expression levels in mice after maternal IMZ exposure. The genes involved in sex hormone receptors, cholesterol synthesis and T synthesis were generally inhibited, and the serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were also decreased in the F0 generation female mice. In addition, after F0 IMZ exposure, ovarian androgen receptor (AR) expression was significantly inhibited, and the androgen levels in the serum increased significantly. This may lead to the appearance of progressive virilization during pregnancy. This phenomenon leads to an aromatase deficiency in the F1 generation mice, which results in a decrease in androgen conversion into estrogen and androgen accumulation. In addition, the mRNA expression of key genes and the serum TC, HDL-C, and LDL-C levels increased in the F1 generation after maternal exposure to IMZ. In addition, testicular TC and LDL-C levels also decreased in the F1 generation male mice. Molecular docking analysis revealed that key hydrogen bonds were formed by nitrogen atoms of the imidazole bonds with Trp751 of the ARs. Our data suggests that maternal IMZ exposure could induce endocrine disruption in the next generation of mice.

A Novel Homozygous CYP19A1 Gene Mutation: Aromatase Deficiency Mimicking Congenital Adrenal Hyperplasia in an Infant without Obvious Maternal Virilisation

Aromatase deficiency is a rare, autosomal recessive disorder in which affected patients fail to synthesize normal estrogen. Herein, we report a 46, XX patient born with virilised external genitalia. A novel homozygous mutation in the CYP19A1 gene, causing aromatase deficiency, was detected. A 30-day infant registered as a male was referred to pediatric endocrinology because of a uterus detected on ultrasonography. The infant was born at 23 gestational weeks by C-section because of preeclampsia and premature membrane rupture. The parents were consanginenous. There was no evidence of virilisation, such as acne, hirsutism, deep voice or clitoral enlargement in the maternal history. Physical examination of the infant revealed complete scrotal fusion and a single urogenital meatus, consistent with Prader stage-3. A standard dose adrenocorticotropic hormone (ACTH) test revealed an inadequate cortisol response and high 17-hydroxy progesterone levels, suggesting simple virilising congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. However, no mutation in the CYP21A2 gene was detected. At age 2.5 years the ACTH test was repeated, after suspension of hydrocortisone treatment for 48 hours, when resulting cortisol and androgen levels were normal. The patient was re-evaluated in terms of 46, XX disorders of sex development (DSD), especially with a suspicion of aromatase deficiency. A novel, homozygous, exon 6 deletion was identified in the CYP19A1 gene. Aromatase deficiency may be confused with CAH in the newborn period. In this case 46, XX DSD aromatase deficiency was present in the absence of a history of maternal virilisation or large and multicystic ovaries.

Aromatase Deficiency due to a Novel Mutation in CYP19A1 Gene

Aromatase deficiency is a rare autosomal recessive genetic disorder with an unknown incidence. Aromatase converts androgens into estrogen in the gonadal and extra-gonadal tissues. Aromatase deficiency causes ambiguous genitalia in the female fetus and maternal virilization (hirsutism, acne, cliteromegaly, deep voice) during pregnancy due to increased concentration of androgens. A 19 months old girl patient was assessed due to presence of ambiguous genitalia. There were findings of maternal virilization during pregnancy. The karyotype was 46,XX. Congenital adrenal hyperplasia was not considered since adrenocorticotropic hormone, cortisol, and 17-hydroxyprogesterone levels were within normal ranges. At age two months, follicle-stimulating hormone and total testosterone levels were elevated and estradiol level was low. Based on these findings, aromatase deficiency was suspected. A novel homozygous mutation IVS7-2A>G (c.744-2A>G) was identified in the CYP19A1 gene. Pelvic ultrasound showed hypoplasic ovaries rather than large and cystic ovaries. We identified a novel mutation in the CYP19A1 gene in a patient who presented with ambiguous genitalia and maternal virilization during pregnancy. Presence of large and cystic ovaries is not essential in aromatase deficiency.

Accelerated Pubertal Tempo in a 46,XY Aromatase-Deficient Patient.

BACKGROUND: Aromatase deficiency is a rare autosomal recessive disorder. 46,XY-affected patients often remain undiagnosed until late puberty. Only 2 pediatric cases have been reported. Data on pubertal development in affected males are scarce. AIM: To report the clinical phenotype and hormonal studies of an aromatase-deficient boy during the prepubertal and early pubertal period. RESULTS: The patient was the older brother of a 46,XX girl with aromatase deficiency. Molecular analysis revealed a previously reported homozygous mutation (Arg192Cys) in the CYP19A1 gene. Pubertal onset was at 9.8 years. At 11.3 years of age, signs of rapidly progressive puberty were seen. Laboratory tests revealed normal pubertal basal and GnRH-stimulated gonadotropin levels, normal Sertoli cell markers, and increased testosterone. The prepubertal lumbar spine bone mineral density (BMD) was normal but pubertal bone mineral accrual was incomplete, leading to osteopenia. CONCLUSION: Estrogen restraint on gonadotropin secretion has been demonstrated in animal and human models. Interestingly, our patient presented with accelerated puberty and apparently normal pituitary gonadal function. These findings suggest that aromatase activity may be required to define pubertal progression in boys. Estrogen deficiency due to aromatase deficiency is responsible for insufficient bone mineral accrual during puberty.

Aromatase Deficiency due to a Homozygous CYP19A1 Mutation in a 46,XX Egyptian Patient with Ambiguous Genitalia.

Aromatase deficiency (AD) is a very rare disorder resulting from mutations in the CYP19A1 gene encoding aromatase, a cytochrome P450 enzyme that plays a pivotal role in androgen conversion to estrogens. AD is inherited in an autosomal recessive trait, and to date only 35 cases have been described in the literature. Herein, we depict a new patient reared as a male, who presented at the age of 21 years with no palpable testis, hypoplastic scrotum, penis-like phallus (3 cm), and penoscrotal hypospadias. The patient was born to consanguineous parents, his karyotype was 46,XX, and SRY was negative. Pelvic sonar showed a small hypoplastic uterus, and no testis could be identified. Serum testosterone was within the reference range of females along with high gonadotropins. Pathology of gonadal biopsy showed ovarian stroma negative for oocytic follicle consistent with streak gonads. All these data were suggestive of AD, which was subsequently confirmed by molecular investigation of the CYP19A1 gene. A homozygous splice site mutation in the donor splice site of exon 9 was identified, c.1263 + 1G>T. This is the first report of such a rare disorder in an Egyptian patient. Our results reinforce the importance of considering AD in patients with 46,XX disorders of sex development after ruling out congenital adrenal hyperplasia.

Aromatase deficiency in a male patient - Case report and review of the literature.

OBJECTIVE: Aromatase, or CYP19A1, is a type II cytochrome CYP450 enzyme that catalyzes the conversion of C19 androgens to C18 estrogens. Its crucial role in both female and male physiology has been deduced from human and animal studies using aromatase inhibitors, genetically altered mice, and patients with aromatase deficiency. The latter is an extremely rare disorder. Its diagnosis is particularly difficult in males, who go through puberty normally and therefore usually present as adults with elevated testosterone, bone abnormalities (e.g., delayed bone age and low bone mass), and metabolic syndrome. In this report, we describe a new case of a male patient with aromatase deficiency harboring a known mutation who presented with less severe clinical and biochemical features. CASE REPORT: The patient presented with low bone mass and delayed bone age after a finger fracture at age 25years. FSH, LH and testosterone levels were normal, but estradiol and estrone levels were absent or barely detectable, raising suspicion for aromatase deficiency. A homozygous c.628G>A mutation in exon 5 was confirmed by direct sequencing. Unlike previously reported cases of aromatase deficiency, he did not display biochemical features of insulin resistance, dyslipidemia, or overweight/obese status. Therapy with estradiol led to the closure of growth plates and a dramatic increase in bone mass. CONCLUSIONS: Here we explore genotype/phenotype associations of this new case compared to cases reported previously. We conclude that the specific nature of mutation c.628G>A, which can potentially result in several different forms of the aromatase enzyme, may lend an explanation to the variable phenotypes associated with this particular genotype.

Aromatase deficiency: a novel compound heterozygous mutation identified in a Chinese girl with severe phenotype and obvious maternal virilization.

BACKGROUND: Aromatase deficiency is a rare autosomal recessive disorder that is caused by an impairment of androgen conversion to estrogens. Affected 46, XX individuals generally present with virilization of external genitalia at birth and mutations in CYP19A1 gene. OBJECTIVE: This study described the clinical features and molecular basis of a Chinese 46, XX girl born with ambiguous genitalia and investigated the functional alteration of two novel mutations of the CYP19A1 gene. METHODS AND RESULTS: Obvious prepartum virilization and remarkably elevated testosterone were observed in the mother, who was initially suspected to have a testosterone-producing ovarian tumor. Clinical phenotypes and hormone profiles of the patient and her mother were investigated. Genotyping analyses of the CYP19A1 gene were performed in the patient and her parents. Functional impairment of the mutations was explored using three-dimensional computer model and mutagenesises in vitro transfection assays. A compound heterozygous mutation of the CYP19A1 gene was revealed in the patient, with a G deletion in nucleotide 264 of exon 3 in one allele and a 23-bp insertion in exon 9 in another allele; both mutations resulted in reading frame-shifts that led to truncated proteins of 87 and 360 amino acids, respectively. Molecular modeling analysis suggested that the two renascent truncated proteins lacked crucial amino acids that were involved in substrate access and catalysis as well as heme-binding region. Functional studies in transfected HEK-293T cells exhibited a nearly complete abolishment of enzyme activity, which may underlie the phenotype and hormone profile. CONCLUSIONS: Two novel CYP19A1 mutations were identified in a Chinese girl born with ambiguous genitalia and severe maternal virilization during pregnancy. Maternal virilization should prompt consideration of aromatase deficiency, preventing unnecessary interventions in pregnancy. This study broadens the spectrum of phenotype and genetic mutations of this rare disorder.

Evolution of steroids during pregnancy: Maternal, placental and fetal synthesis.

Progesterone, estrogens, androgens and glucocorticoids are involved in pregnancy from implantation to parturition. Their biosynthesis and their metabolism result from complex pathways involving the fetus, the placenta and the mother. The absence of expression of some steroïdogenic enzymes as CYP17 in placenta and in adrenal fetal zone and the better determination of the onset and variation of others especially HSD3B2 during the pregnancy explain the production of the steroid hormones. Moreover the consequences of some disorders of steroidogenesis (especially aromatase, POR, CYP11A1 and 21-hydroxylase deficiencies) in fetus and mother during the pregnancy have permit to elucidate these complex pathways. This better knowledge of steroid hormones production associated with their dosages in maternal plasma/urine or amniotic fluid using new specific assays as LC-MS MS could facilitate the follow-up of normal and pathological pregnancies. Moreover, these advances should be a basis to evaluate the impact of multiple pathologies of the pregnancy and pharmacologic and xenobiotic consequences on their metabolism.

Aromatase deficiency in a Chinese adult man caused by novel compound heterozygous CYP19A1 mutations: effects of estrogen replacement therapy on the bone, lipid, liver and glucose metabolism.

OBJECTIVES: Aromatase deficiency is a rare disorder resulting in estrogen insufficiency in humans. It has been reported in remarkably few men with loss-of-function mutations in the CYP19A1 gene encoding the aromatase, a cytochrome P450 enzyme that plays a crucial role in the biosynthesis of estrogens from androgens. We investigated a non-consanguineous family including an adult man with clinical features of aromatase deficiency, and studied the effects of estrogen replacement in the man. METHODS: We investigated the clinical and biochemical phenotype, performed CYP19A1 mutational analysis in the family and 50 unrelated persons, studied the effects of CYP19A1 mutations on aromatase protein structure, functionally characterized the mutations by cell-based aromatase activity assays, and studied the effects of estrogen replacement on the bone, lipid, liver and glucose metabolism. RESULTS: The man with clinical features of aromatase deficiency had novel compound heterozygous CYP19A1 mutations (Y81C and L451P) that were not found in 50 unrelated persons. Three-dimensional modeling predicted that Y81C and L451P mutants disrupted protein structure. Functional studies on the basis of in vitro expression showed that Y81C and L45P mutants significantly decreased the aromatase activity and catalytic efficiency. Estrogen replacement in the man increased bone mineral density, accelerated bone maturation, improved lipid profile and liver steatosis, and improved glucose levels but not insulin resistance. CONCLUSIONS: We have identified two novel CYP19A1 missense mutations in an aromatase-deficient man. Estrogen replacement in the man shows great impact on recovering the impairments in the bone, lipid, liver and glucose metabolism, but fails to improve insulin resistance.

Aromatase and estrogen receptor α deficiency.

Studies on the phenotypes of women and men with mutations disrupting estrogen biosynthesis and action have significantly advanced our knowledge of the physiologic roles of estrogen in humans. Aromatase deficiency results from autosomal recessive inheritance of mutations in the CYP19A1 gene. It gives rise to ambiguous genitalia in 46,XX fetuses. At puberty, affected girls have hypergonadotropic hypogonadism, do not develop secondary sexual characteristics, and exhibit progressive virilization. The affected 46,XY men have normal male sexual differentiation and pubertal maturation. These men, however, are extremely tall and have eunucoid proportions with continued linear growth into adulthood, severely delayed epiphyseal closure, and osteoporosis due to estrogen deficiency. Although estrogen has been shown to be essential for normal sperm production and function in mice, its role in fertility is not clear in men. Thus far, one man and an unrelated woman with estrogen resistance due to mutations in the estrogen receptor α (ESR1) gene have been described. Their clinical presentations are similar to that of aromatase-deficient men and women.