To report this case, appropriate written consent and assent had been obtained in accordance with the guidelines of the ethics committee of Sun Yat-sen Memorial Hospital, Sun Yat-sen University (SYSEC-KY-KS-2019-052).
Clinical and biochemical presentation
The patient was born at term after a normal pregnancy and delivery. Her parents were nonconsanguineous and she had a healthy and fertile brother. At birth, she was healthy and had external female genitalia. At 16 years old, she presented with normal breast development, no pubic or axillary hair, normal blood pressure, but no menses, and she was evaluated for primary amenorrhea by a local gynecologist. Her karyotype was 46,XX and a pelvic ultrasound revealed the presence of 4×3×4cm ovarian cyst in the left ovary and an infantile uterus (hormonal data are not available). However the etiology of her amenorrhea remained unknown at that time. After that, she had accepted hormone replacement therapy(HRT) to establish a regular menstrual cycle but her menses didn’t come when she stop HRT. When she was 29 years old and had suffered from primary infertility for three years, she was referred to treat infertility and she had a cancelled cycle of ovulation induction in the local hospital. The follicle growth and sex hormone changes during the ovulation induction were as the following : human menopausal gonadotropin(HMG)(150IU/d) were administered for 17 days from the cycle 3 of inducing menstruation after two-month oral contraception pills, and two follicles grew to 18mm and 17mm in size but serum E2 level remained very low (<5pg/ml) with P level increasing to 25.1ng/ml and a thin endometrium (3mm). Ovulation trigger was cancelled due to the thin endometrium and the abnormal levels of E2 and P.
Then she was referred to Reproductive Medicine Center of Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University in 2014, willing to have a child. Physical examination revealed the following characteristics: a height of 158cm and weight of 60kg; Tanner scores of four for the breasts and two for axillary and pubic hair; female external genitalia; difficulty of bending the metacarpopha-langeal joints from childhood ; no other skeletal malformations were founded. No other infertility factor was identified. The evaluations for adrenal, gonadal and pituitary hormones showed that serum levels of P and 17-hydroxyprogesterone(17-OHP) were obvious high, and dehydroepiandrosterone sulfate(DHEA-S), androstenedione, free testosterone were low, as well as the other tests were within the reference ranges. Table 1 summarized the clinical characteristics and hormonal profiles of the patient. A pelvic ultrasonography showed a hypoplastic uterus, thin endometrium and an ovarian cyst(2.9×3.0×2.8cm) in the right ovary. Bilateral integration of the adrenal glands was enlarged, as determined by a computed tomography scan.
Genetic testing
The patient was suspected of having rare forms of CAH according to the clinical manifestations, imaging and laboratory tests. In order to confirm the diagnosis and find the genetic etiology, a panel of CAH candidate genes by targeted exome next-generation sequencing (NGS) were performed, including CYP21A2,CYP19A1,CYP17A1,CYP11A1, HSD3B2, STAR,AR,EDNRA,NR5A1,PDE8B and POR gene.
Genomic DNA were extracted from the peripheral blood leukocytes using the QIAamp DNA Blood Mini Kit (Qiagen, Hilden, Germany). The extracted DNA was segmented by DNA enzyme and purified by magnetic bead(Beckman Inc.,USA), followed by PCR amplification. DNA library was captured and purified twice by a customized Panel probe (Illumina Inc.,USA). The exon, intron-exon boundaries, the 5’and 3’ flanking regions of the panel genes was sequenced by NextSeq500 (Illumina Inc.,USA).
Raw data was compared with reference sequence retrieved from the University of California at Santa Cruz Genome Browser (http://genome.ucsc.edu) (UCSC,hg19) by the BWA algorithm and annotated using the method reported by Zhang[29]. The HGVS (www.hgvs.org/mutnomen/) guidelines for describing sequence variations and numbering were used, with +1 corresponding to the A of the ATG translation initiation codon of the GenBank cDNA sequence and the amino acid sequences. All variants were classified according to the American College of Medical Genetics and Genomics (ACMG) 2015 classification[24]: pathogenic, likely pathogenic, uncertain significance, likely benign and benign. Sanger sequenced was performed in suspected variations.
The results showed that no mutation and copy number variation were found in CYP21A2,CYP19A1,CYP17A1,CYP11B1,HSD3B2,AR,EDNRA,NR5A1,PDE8B and STAR, but a compound heterozygous mutation was found in POR gene(NM_000941.2): c.1370G>A (p.Arg457His,rs28931608,) and c.1196_1204del (p.Pro399_Glu401del ) [Figure 1]. The sequencing results of her parents showed that her father was a heterozygous carrier for c.1370G>A and her mother was a heterozygous carrier for c.1196_1204del. The c.1370G>A had been found in some PORD patients(HGMD:CM040474), which are common in Japanese and Chinese patients [2,7,9,12,13]. The mutation of c.1370G>A in POR gene leads to a conversion of arginine at amino acid position 457 to histidine (R457H) which supports only 3% of 17-hydroxylase activity, no detectable 17,20 lyase activity [12,15], and only 1% of aromatase activity [22]. The c.1196_1204del mutation in POR gene was firstly reported in two unrelated Turkish PORD patients(HGMD ID:CD117091) and cause a loss of three amino acid p.Pro399_Glu401del (P399_E401del)[11] . In comparison to wild-type POR, this P399_E401del mutation was found to decrease catalytic efficiency of 21-hydroxylase by 68%, 17α-hydroxylase and 17,20 lyase by 76% and 69%, and aromatase by 85%[5,11]. The variants c.1370G>A and c.1196_1204del were classified by pathogenic and likely pathogenic respectively according to ACMG.
Diagnosis and differential diagnosis
The elevation of serum basal morning 17OHP concentration is usually used to diagnosis the other types of CAH such as 21-hydroxylase or 11β-hydroxylase deficiency, while the major clinical presentation in these two types of CAH are atypical genitalia, precocious pubarche, hirsutism, oligomenorrhea/amenorrhea and without sex steroid deficiency and skeletal malformation[8]. Our case presented with no signs of virilization or clinical/biochemical hyperandrogen, but impaired estradiol production, primary amenorrhea and minor skeletal malformation. Those are the clinical features of PORD[8]. Additional genetic testing also confirmed the PORD diagnosis.
Fertility treatment
According the clinical presentation, the results of biochemical tests and genetic testing the patient was diagnosed as PORD. Then she was given HRT composed of estradiol and progesterone (Femoston, Abbott Biologicals B.V, Netherland), combined with oral dexamethasone (0.375mg/d) for two months. After the therapy her basal serum P and 17-OHP levels fell to normal levels(0.35ng/ml and 0.23ng/ml respectively) with disappearance of the ovarian cyst. According to our several successful cases with atypical CAH caused by 17α-hydroxylase deficiency through frozen embryo transfer after IVF and the pregnant case with 17α-hydroxylase deficiency published in 2016[4] who showed similar changes of sex hormones and inadequate endometrial development during ovarian stimulation, IVF management was recommended. Oral dexamethasone(0.375 mg/d) was maintained during all treatment phases.
Ovarian stimulation for IVF
We performed a long gonadotropin releasing hormone agonist (GnRHa) protocol with down regulation using a single dose of 1.3mg long-acting triptorelin and ovarian stimulation with 225IU/d of recombinant FSHα(rFSH) and 75IU/d HMG. When four follicles reached to 20 mm, 19mm,16mm and 15mm in diameter, 10,000IU of human chorionic gonadotropin(HCG) was administered for triggering the maturation of oocytes on Day 21 of stimulation. On the triggering day serum levels of E2 and P were 33pg/ml and 2.3ng/ml respectively with a thin endometrium (4mm), which showed less disorder comparing with them in the cycle of ovulation induction without oral dexamethasone and GnRH agonist down regulation. Then 4 oocytes were retrieved 36 hours after HCG triggering and 4 cleavage embryos were available and cryopreserved. The details were shown in Table 2.
Pregnancy after frozen-thawed embryo transfer with artificial endometrial preparation
The patient’s menses came 17 days after oocyte retrieval. On cycle 3 serum P level was 0.6 ng/ml and artificial endometrial preparation was started with oral estradiol valerate (4mg/d). When endometrial thickness reached 10.4mm, progesterone in oil(60mg/d) was administered by intramuscular injection, and 3 days later, two frozen-thawed embryos were transferred. After embryo transfer, oral dexamethasone wasn’t given any longer considering the patient had never presented with adrenal insufficiency before. A twin pregnancy was attained and estradiol and progesterone was maintained during the first trimester of pregnancy. The pregnancy proceeded uneventfully, with the regular monitor in the department of Endocrinology and Obstetrics. A healthy boy and a healthy girl were delivered by caesarean section after 37 weeks and 2 days of gestation, weighing 2.5kg and 2.3kg respectively. No perinatal problems were observed, and the puerperium was uneventful. During the pregnancy and post-partum period, she had not presented with adrenal insufficiency and no need for glucocorticoids replacement. She remained amenorrhea one year after delivery and has been accepting HRT until now.
Literature search
We searched the PubMed database using search terms for Medical Subject Headings and/or text words relating to PORD and pregnancy. The retrieved papers were hand-searched for additional relevant articles using our inclusion criteria (papers reporting POR gene mutations in 46, XX females). Only two papers and three female cases with homozygous or compound heterozygous mutations in POR gene were reported to be successful pregnant (23,26). Including our case, all four successful pregnant cases were obtained by IVF and no spontaneous pregnancy has been reported (Table 3).