Mayer-Rokitansky-Kuster-Hauser (MRKH) Syndrome

Definition

• Incidence: approximately 1 in 4,000-5,000 live female births
• Second only to gonadal dysgenesis as a cause of primary amenorrhea, accounting for 10-15% of primary amenorrhea cases

Classification

• Müllerian duct aplasia
• Renal aplasia
• Cervicothoracic Somite dysplasia (e.g., Klippel-Feil syndrome)

Embryology / Pathogenesis

• Normal vaginal development requires induction of the sinovaginal bulbs by the uterovaginal primordium to form the vaginal plate
• In MRKH, this induction fails - the hymenal fringe is usually preserved (urogenital sinus-derived), explaining the shallow vaginal dimple
• The uterovaginal canal develops during a period when other mesodermally derived organs are also forming - this explains the multi-system associations
• Maternal deficiency of galactose-1-phosphate uridyltransferase has also been associated with Müllerian aplasia

Genetics (2026 Update)

• WNT4 - a WNT4 mutation resembling MRKH phenotype was a key early discovery; WNT4 is essential for Müllerian duct formation
• HOXA family, TBX6, GREB1L, LHX1, LRP10, PAX8, GATA3
• Copy number variants (CNVs) in chromosomal regions: 17q12, 16p11, 1q21-q22, 22q11, 1q44, 16p13.3, Xp22.3
• HNF1B (low prevalence of mutations but CNVs found)
• Epigenetic factors: no consistent patterns identified yet

Clinical Features

Primary Presentation

• Primary amenorrhea - the most common presentation, typically discovered after the expected age of menarche
• Infertility
• Dyspareunia or inability to have sexual intercourse

Examination

• Normal external genitalia and secondary sexual characteristics (normal breast development, pubic/axillary hair, body habitus)
• Normal karyotype: 46,XX
• Normal LH and FSH levels
• Normal ovaries with intact ovarian function (normal estrogen levels)
• Only a shallow vaginal pouch/dimple present on examination
• Absence of uterus on pelvic imaging
• Inguinal hernia is less common than in complete androgen insensitivity syndrome (an important differentiating point)

Uterine/Müllerian Anatomy (from series of 91 patients):

• ~25% - complete uterine absence
• ~55% - solid rudimentary uterus
• ~30% - other uterine abnormalities
• Fallopian tubes: normal in 32%, rudimentary in ~50%, absent in 10%
• Ovaries: always present and functional

Cyclical Abdominal Pain

Associated Anomalies

Renal (most common, ~1/3 of all patients; ~68% of Type B)

• Unilateral renal agenesis
• Renal ectopia (pelvic kidney, horseshoe kidney)
• Double urinary collecting system
• Note: The converse is also important - genital anomalies occur in 25-89% of females with renal anomalies

Skeletal (10-20% of cases)

• Klippel-Feil syndrome (cervical vertebral fusion/failure of segmentation) - found almost exclusively in Type B
• Scoliosis, vertebral fusions
• Upper limb abnormalities (Sprengel deformity)

Cardiac (~16% of MRKH patients)

• Various congenital heart defects

Auditory

• Hearing impairment (reported in MRKH Type B)

Differential Diagnosis

Investigations

First Line

• Pelvic ultrasound (2D/3D) - first-line imaging; identifies absent uterus and renal anomalies

Gold Standard

• MRI (pelvis) - more sensitive and specific; sagittal and axial T2-weighted sequences accurately define Müllerian anatomy, distinguish Type A from Type B, and guide management

Additional

• Karyotype (46,XX) - confirms chromosomal sex, excludes CAIS
• Serum FSH, LH, estrogen, testosterone - confirm normal ovarian function and exclude androgen disorders
• Renal imaging - evaluate for associated renal anomalies (IVP or renal ultrasound)
• Skeletal survey - if vertebral anomalies suspected

Management

Vaginal Reconstruction (Neovagina)

• Frank dilation (1938) - self-directed progressive vaginal dilation using dilators of increasing size
• Ingram bicycle seat stool method (1981) - modified progressive dilation technique
• Success rates comparable to surgery in motivated patients

• McIndoe vaginoplasty - creation of a neovaginal space lined with a split-thickness skin graft
• Bowel vaginoplasty (Hendren & Atala) - use of bowel segments; useful in complex cases
• Other flap-based approaches - perineal skin flaps

Management of Hematometra/Functional Uterine Remnant

• Hemiuterus present: surgical removal is recommended
• Midline uterine remnant: hormonal suppression (not surgical connection to neovagina due to poor outcomes)

Fertility Options

• Oocyte retrieval + gestational surrogacy - the standard fertility option (own genetic eggs, surrogate uterus)
• Uterine transplantation (UTx) - an evolving option:
  • First successful live birth reported in Sweden in 2014 (Brannstrom et al.)
  • First trial included 9 women; 2 required premature graft removal; multiple live births reported
  • By 2018, 17 uterine transplants were reported worldwide (5 groups), with 8 grafts requiring premature removal
  • UTx is increasingly available internationally but remains resource-intensive

Psychological Support

• Counseling for grief (loss of fertility, gender identity concerns)
• Sexual health counseling
• Family support
• Long-term psychosexual support - important given the impact on identity, relationships, and fertility

Prognosis

• Normal life expectancy
• Normal sexual function achievable with vaginal creation (dilation or surgery)
• Genetic motherhood possible via oocyte retrieval and either surrogacy or uterine transplantation
• Ovarian function is preserved - normal hormonal profiles, no premature menopause

• Campbell-Walsh-Wein Urology, pp. 1261-1263, 1308 (Sections: Vaginal Agenesis / MRKH / Unclassified Forms)
• Berek & Novak's Gynecology, p. 1874 (Müllerian Anomalies / Primary Amenorrhea)
• Grainger & Allison's Diagnostic Radiology, p. 889 (Class I Uterine Agenesis)
• Christopoulos et al. (2026). Genetic background of MRKH: A systematic review. Best Pract Res Clin Obstet Gynaecol.