Loss of Function of the Nuclear Receptor NR2F2, Encoding COUP-TF2, Causes Testis Development and Cardiac Defects in 46,XX Children

Abstract

Emerging evidence from murine studies suggests that mammalian sex determination is the outcome of an imbalance between mutually antagonistic male and female regulatory networks that canalize development down one pathway while actively repressing the other. However, in contrast to testis formation, the gene regulatory pathways governing mammalian ovary development have remained elusive. We performed exome or Sanger sequencing on 79 46,XX SRY-negative individuals with either unexplained virilization or with testicular/ovotesticular disorders/differences of sex development (TDSD/OTDSD). We identified heterozygous frameshift mutations in NR2F2, encoding COUP-TF2, in three children. One carried a c.103_109delGGCGCCC (p.Gly35Argfs∗75) mutation, while two others carried a c.97_103delCCGCCCG (p.Pro33Alafs∗77) mutation. In two of three children the mutation was de novo. All three children presented with congenital heart disease (CHD), one child with congenital diaphragmatic hernia (CDH), and two children with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). The three children had androgen production, virilization of external genitalia, and biochemical or histological evidence of testicular tissue. We demonstrate a highly significant association between the NR2F2 loss-of-function mutations and this syndromic form of DSD (p = 2.44 × 10−8). We show that COUP-TF2 is highly abundant in a FOXL2-negative stromal cell population of the fetal human ovary. In contrast to the mouse, these data establish COUP-TF2 as a human “pro-ovary” and “anti-testis” sex-determining factor in female gonads. Furthermore, the data presented here provide additional evidence of the emerging importance of nuclear receptors in establishing human ovarian identity and indicate that nuclear receptors may have divergent functions in mouse and human biology.

Retinoic Acid Antagonizes Testis Development in Mice

“…Our findings are particularly congruent with those of Jørgensen et al (2015), who cultured human fetal testis tissue from 7-9 weeks of gestation for 2 weeks in 1 mM RA and found that SOX9 and DMRT1 were unchanged but AMH expression was lost, and COUP-TFII, a marker of fetal Leydig and peritubular myoid cells, was greatly upregulated. Interestingly, very recent studies found evidence that COUP-TFII acts in a pro-ovary and anti-testis manner in humans (Bashamboo et al, 2018). Further, our findings complement a study revealing pro-ovarian activity of ectopic RA in the adult testis (Minkina et al, 2014).…”

Disorders of Sex Development—Novel Regulators, Impacts on Fertility, and Options for Fertility Preservation

“…The orphan nuclear receptor NR2F2 gene, which encodes the transcription factor chicken ovalbumin upstream promoter transcription factor 2 (COUP-TF2), has been described as a "pro-ovary and anti-testis" gene following the identification of two frameshift variants in three syndromic 46,XX children, one with ovarian dysgenesis and the other with OT DSD, associated with congenital heart disease and variable somatic anomalies including blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) [81]. A 3 Mb deletion containing the NR2F2 gene was also described in an individual with 46,XX OT DSD with a similar phenotype [82].…”

“…The precise mechanism by which COUP-TF2 defects leads to 46,XX DSD has not been elucidated. However, at the initiation of ovarian development, FOXL2 and COUP-TF2 appear to be mutually exclusive at the cellular level, with distinct location in the somatic and stromal cells of the fetal ovary, respectively [81]. COUP-TF2 is expressed at the same time as WT1 in early gonadal embryogenesis [83] and it regulates negatively the expression of the pro-testis Sox9 gene in the osteogenic mesenchyme.…”

NR5A1gene variants repress the ovarian-specific WNT signaling pathway in 46,XX disorders of sex development patients

“…Another common cause is ectopic SRY‐box 9 ( SOX9 ) expression, often caused by duplications in the upstream enhancer (Croft, Ohnesorg, & Sinclair, ). Loss of function variants in ovarian pathway genes (e.g., R‐Spondin 1 [ RSPO1 ]) have been identified in a small subset of syndromic 46,XX (ovo)testicular DSDs (Bashamboo et al., ; Parma et al., ; Tomaselli et al., ). Despite these known causes, SRY‐negative 46,XX (ovo)testicular DSDs have a diagnostic rate much lower than that of other DSDs (Eggers et al., ) highlighting a need to identify novel genes or genetic variants underlying these DSDs.…”