Primary amenorrhoea — Turner, CAIS and MRKH structured SAQ (15 marks)

(a) Diagnosis and confirmatory test (3 marks)

One mark per point, maximum three. ^[1]

• Diagnosis: Mayer-Rokitansky-Kuster-Hauser syndrome — Mullerian agenesis. Normal breast development with normal pubic hair means normal ovarian oestrogen and intact androgen action; the absent uterus with present ovaries and a blind vagina is the MRKH phenotype.
• Confirmatory test: a full karyotype. In MRKH it returns 46,XX; the test simultaneously excludes complete androgen insensitivity syndrome (46,XY), which can present identically apart from the androgen-dependent hair.
• One supporting sentence earns the third mark: gonadotrophins and testosterone will be in the normal female range in MRKH — elevated LH with male-range testosterone would point to androgen insensitivity instead.^[1][3]

(b) The CAIS discriminator (4 marks)

One mark per question correctly framed with the direction of the answer. ^[3]

• Androgen-dependent hair: in MRKH, pubic and axillary hair are normal because the androgen receptor works. In CAIS the receptor is broken, so pubic and axillary hair are scanty despite male-range testosterone.
• Karyotype plus gonadotrophins: MRKH is 46,XX with normal FSH and LH; CAIS is 46,XY with a high LH because the hypothalamic-pituitary axis senses no androgen effect.
• Ovaries: MRKH has normal ovaries that produce normal oestrogen and can yield oocytes; CAIS has testes in the abdomen, inguinal canal or labia, and no ovaries.
• The synthesis mark: state that the discrimination matters because management diverges — MRKH keeps her gonads for life while CAIS carries a gonadal germ-cell tumour question that drives the gonadectomy-timing conversation.^[2][3]

(c) Investigations once the karyotype is 46,XX (4 marks)

One mark per investigation with justification. ^[1]

• Renal imaging (ultrasound or CT urogram): renal agenesis or ectopia accompanies Mullerian agenesis in about a third of cases — a single pelvic kidney changes everything from haematuria workup to future surgery.
• Skeletal survey or targeted spinal imaging: vertebral and skeletal anomalies are over-represented (around a tenth of patients) and flag the MURCS association.
• Pelvic MRI: defines any rudimentary Mullerian structures and rules out a functioning endometrial remnant, which can cause cyclical pain and needs excision.
• Hearing assessment and a focused family history: auditory anomalies form part of the wider association spectrum, and a careful history picks up the rare familial forms.^[1]

(d) First-line management, fertility and prognosis (4 marks)

One mark per point. ^[1]

• Counselling first: the psychological impact of the diagnosis is the dominant morbidity. Offer named clinical-psychology support and peer-connection resources before any anatomical treatment.
• First-line functional treatment is primary vaginal dilation, taught by an experienced team when the patient chooses it — 90 to 96 per cent of well-supported patients reach anatomical and functional success. Surgical neovagina is reserved for dilation failure and belongs in expert hands.
• Fertility pathway: her ovaries are normal, so her own oocytes can be retrieved by IVF and carried by a gestational surrogate; adoption and, at specialist centres, uterine transplantation are the alternatives.
• Prognosis statement: with counselling and dilation she can expect a fully feminised adulthood with normal sexual function; nothing about MRKH shortens life, limits hormones or prevents genetic parenting — the loss is the uterus, not the ovaries.^[1][4]