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

Long-term outcomes in non-CAH 46,XX DSD

Differences/disorders of sex development (DSD) comprise a large group of rare congenital conditions. 46,XX DSD, excluding congenital adrenal hyperplasia (CAH), represent only a small number of these diseases. Due to the rarity of non-CAH 46,XX DSD, data on this sex chromosomal aberration were confined to case reports or case series with small numbers of patients. As the literature is still relatively sparse, medical data on the long-term effects of these pathologies remain scarce. In this review, we aim to provide an overview of current data on the long-term follow-up of patients with non-CAH 46,XX DSD, by covering the following topics: quality of life, gender identity, fertility and sexuality, global health, bone and cardiometabolic effects, cancer risk, and mortality. As non-CAH 46,XX DSD is a very rare condition, we have no accurate data on adult QoL assessment for these patients. Various factors may contribute to a legitimate questioning about their gender identity, which may differ from their sex assigned at birth. A significant proportion of gender dysphoria has been reported in various series of 46,XX DSD patients. However, it is difficult to give an accurate prevalence of gender dysphoria and gender reassignment in non-CAH 46,XX DSD because of the rarity of the data. Whatever the aetiology of non-CAH 46,XX DSD, fertility seems to be impaired. On the other hand, sexuality appears preserved in 46,XX men, whereas it is impaired in women with MRKH syndrome before treatment. Although there is still a paucity of data on general health, bone and cardiometabolic effects, and mortality, it would appear that the 46,XX DSD condition is less severely affected than other DSD conditions. Further structured and continued multi-center follow-up is needed to provide more information on the long-term outcome of this very rare non-CAH 46,XX DSD condition.

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.

Structures and Functions of Human Placental Aromatase and Steroid Sulfatase, Two Key Enzymes in Estrogen Biosynthesis

Cytochrome P450 aromatase (AROM) and steroid sulfatase (STS) are the two key enzymes for the biosynthesis of estrogens in human, and maintenance of the critical balance between androgens and estrogens. Human AROM, an integral membrane protein of the endoplasmic reticulum, is a member of the cytochrome P450 superfamily. It is the only enzyme to catalyze the conversion of androgens with non-aromatic A-rings to estrogens characterized by the aromatic A-ring. Human STS, also an integral membrane protein of the endoplasmic reticulum, is a Ca²⁺-dependent enzyme that catalyzes the hydrolysis of sulfate esters of estrone and dehydroepiandrosterone to the unconjugated steroids, the precursors of the most potent forms of estrogens and androgens, namely, 17β-estradiol, 16α,17β-estriol, testosterone and dihydrotestosterone. Expression of these steroidogenic enzymes locally within organs and tissues of the endocrine, reproductive, and central nervous systems is the key for maintaining high levels of the reproductive steroids. The enzymes have been drug targets for the prevention and treatment of diseases associated with steroid hormone excesses, especially in breast, endometrial and prostate malignancies. Both enzymes have been the subjects of vigorous research for the past six decades. In this article, we review the important findings on their structure-function relationships, specifically, the work that began with unravelling of the closely guarded secrets, namely, the 3-D structures, active sites, mechanisms of action, origins of substrate specificity and the basis of membrane integration. Remarkably, these studies were conducted on the enzymes purified in their pristine forms from human placenta, the discarded and their most abundant source. The purification, assay, crystallization, and structure determination methodologies are described. Also reviewed are their functional quaternary organizations, post-translational modifications and the advancements made in the structure-guided inhibitor design efforts. Outstanding questions that still remain open are summarized in closing.

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.