Male and Female Puberty, Pubertal hormones & Disorders of Sexual Development😍

Puberty Hormonal Regulation

Pre-pubertal Stage:

• Continuous release of GnRH.
• This inhibits LH and FSH.

• Maintained by GABA and Melatonin.

Puberty Onset:

1. ↑↑ Kisspeptin 
• acts via GPR54 on GnRH neuron
• Pulsatile release of GnRH.

2. Pulsatile release of GnRH leads to:
• LH release → when GnRH ↓
• FSH release → when GnRH ↑

3. Primarily due to Pulsatile secretion of GnRH (Leptin helps) from hypothalamus.
• Adequate fat stores → ↑ Leptin.
• Leptin has a permissive role in puberty.

• Mnemonic: At puberty → Leap (Leptin) and Kiss (Kisspeptin)

Leptin Roles

1. Female Puberty

• Mnemonic:
• Granpa (Granulosa) had aroma (Aromatase) Fishy smell (FSH)
• it was time to inhibit (Inhibin) himself → but he was still active (Activin)
• Lady (Leydig) → with the Thekkal (Theca) history
• Lady came near granpa → Granpa on ayi → anterior (Anterior pituitary) pongi
• Lady when near granpa → got aroma () of fish ()→ aroma karanam ladykk full androgenum estrogen ayi→ Estrogen, Progestogen () on ayi → Thalachoru (hypothalamus) inhibit (Negative feeedback) ayi

Age of Onset

• Females: 10.5 years (average)

• Males: 11.5 years (average)

First Sign of Puberty

• Females: Growth Spurt (most specific: Thelarche - breast development).

• Males: Testicular enlargement.

Sequence of Puberty in Females

• Growth Spurt > Thelarche (breast development) > Pubarche (pubic hair) > Peak Height Velocity > Menarche (first menstruation).

Androgen

Role of Estrogen in Puberty (in Females)

• Breast development.

• Development of reproductive tract: uterus development.

• Starting of menstruation.

• Pubertal growth spurt.

• Vaginal cornification.

• Cervical mucus production.

• Epiphyseal closure (bone growth stops).

• Bone mass.

• Increased clotting factors

• OCP (C/I) in
• H/O thromboses/CVA/CAD.
• Puerperium (< 21 days).

Delayed Puberty

• Females: Puberty not started by 13 years.

• Males: Puberty not started by 14 years.

• Most common cause (m/c): Constitutional delay.

• Drug of choice (DOC): Pulsatile GnRH.

Hormones Responsible

• Main hormone responsible for breast development: Estrogen.

• Main hormone responsible for pubic hair and axillary hair development: Androgen.

Precocious Puberty (Puberty Onset too Early)

• Females: Thelarche < 8 years of age.

• Males: Testicular enlargement ≤ 9 years of age.

• Most common cause in both: Central precocious puberty.

• More common in: Females > Males.

Types of Precocious Puberty

1. Central Precocious Puberty

• Definition: Premature activation of the HPO axis.

• Hormone Levels: 
• LH and FSH are increased;
• Estrogen and Inhibin are increased.

• Most common cause: Idiopathic (80%).

• Second most common cause: Brain hamartoma (10%).

• Always isosexual (secondary sexual characteristics match the biological sex).

• Drug of choice: Continuous GnRH

• Associated with: Menstruation before 10 years.

2. Peripheral Precocious Puberty

• Definition: Exogenous source of estrogen/androgen, not HPO axis activation.

• Can be isosexual (matches sex) or heterosexual (cross-sex characteristics).

• Hormone Levels: LH and FSH are decreased.

• Causes:
• Isosexual (matches sex):
• Estrogen-secreting ovarian tumor.
• Hypothyroidism.
• McCune Albright Syndrome.
• Heterosexual (cross-sex):
• Androgen-secreting tumor.
• Congenital Adrenal Hyperplasia (CAH).

• Not associated with: Menstruation.

Important Notes on Precocious Puberty

• McCune-Albright Syndrome:
• GNAS 1 mutation
• α unit of G Protein

• A syndrome associated with fibrous dysplasia.
1. Polystotic Fibrous Dysplasia: 
• Fibrous dysplasia affecting multiple bones (multicentric).
2. Pigmentation: 
• "Café au lait" → Coast of Maine
• Rough/irregular margins
3. Precocious Puberty: 
• Early onset of puberty.

• A/W Myxoma

• Mnemonic:
• Mccune was all bright (chinese guys → Fibrous dysplasia)
• But got precocious puberty and
• Disgusting (dysplastic) fibrous (FD) with spots (CAL)

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Café au lait

• Regular and well-demarcated margins / Smooth border:
• Called Coast of California.
• Usually seen in NF1.

• Irregular margins/ Rough border:
• Called Coast of Maine.
• Classic feature of McCune-Albright syndrome
• Usually seen in segmental pigmentary disorders.
• Can be present in Leopard syndrome or Tuberous Sclerosis.

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• Significant Neurotransmitters
• GABA: Maintains dormancy of hypothalamus before puberty.
• Kisspeptin: Pulsatile release of GnRH at puberty.
• Leptin: Permissive role in puberty onset.

A 5 year old boy was brought with complaints of growth of pubic hair. O/E – Child tall for his age with deepening of voice. Apart from presence of pubic hair, there was increase in testicular size both sides and increased penile length. Which among the following is/are NOT likely in this child?
(A) Hypothalamic hamartoma
(B) Pituitary adenoma
(C) Adrenocortical tumor
(D) Both (A) and (B)

2. Male Puberty

Sertoli Cell vs Leydig Cell

Cells	Notes
Sertoli Cell	• Contains receptors for FSH and androgens • Forms blood-testis barrier → Tight junction • “Nurse cells of testis” ↳ Nourishes and protects developing sperm cells Functions • Inhibin → Inhibit FSH • Androgen-binding protein (ABP) → Bind to testosterone • AMH (MIS) → causes regression of Müllerian ducts • Aromatase enzyme → converts testosterone to estradiol • Phagocytic function → Ingest dead sperms
Leydig Cell	• Contains LH receptors • Synthesizes cholesterol de novo • Acquires cholesterol via LDL & HDL receptors ↳ (scavenger receptor) • Expresses high levels of 3β-HSD ↳ (converts androstenedione to testosterone) • Testosterone diffuses into seminiferous tubules • In tubules, aromatase of Sertoli cells converts testosterone into estradiol

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AMH

• Glycoprotein hormone

• Gene for MIS/AMH
• Chromosome 19

• Produced by
• Sertoli cells at 7 weeks
• Granulosa cells of preantral and small antral follicles

• Function: Regression of Mullerian Duct in males.

• Best test for Ovarian reserve
• Done any day

• 1 - 3 = Normal

• High AMH
• > 3: PCOS
• > 3.3: High risk of OHSS
• Good outcome of IVF

• Low AMH
• <1 = Suggestive of POI (Poor Ovarian reserve)
• <0.5 = Diagnostic of POI

Scrotum Temperature

• Scrotum temperature is 1-2°C less than body temperature

• This lower temperature favors spermatogenesis.

Sperm Development during Puberty

• During puberty, cells transform into sperms.

• Sperm structure includes:
• Head
• Midsection
• Tail

• Sperm continues to develop in the epididymis for 2 to 4 weeks (20 days)

Sperm Capacitation

• Occurs after ejaculation into female genital tract.

Events Before Fertilisation

• Capacitation:
• Ability of sperms to fertilize ova
• Time: 6-8 hours.
• Site:
• Begin → cervix
• Completed → fallopian tube

• Acrosomal reaction:
• Head of sperm enters cortex of 2˚ oocyte
• Due to hyaluronidase released by acrosomal cap
• Penetrate Zona pellucida
• Zona pellucida:
• Acellular layer
• Has ZP3 Glycoprotein (most abundant)
• Main receptor for sperm
• Mnemonic: ZP3 → Zperm
• Influx of calcium

• Zona reaction >> Cortical reaction:
• Prevents: Polyspermy
• Release of enzymes by cortex of 2˚ oocyte
• Zona pellucida made impermeable to other sperms

Semen Components (Fluid)

Produced by:

• Seminal vesicle (60%):
• Fructose: Energy source (GLUT-5 mediated).
• Vit C: Antioxidant.
• Prostaglandin: Makes cervical mucus penetrable by sperm.
• Phosphorylcholine:
• Detected via Florence test (Test for seminal stain in rape cases).

• Prostate (30%):
• Fibrinolysin: Liquefaction of semen in 15-30 min.
• Acid phosphatase
• Spermine: Detected via Barberio's test.
• Zinc

• Vas deferens (10%):
• Bicarbonate.
• Phosphate.

• Buffers: Bicarbonate, phosphate.

• Mnemonic: Barber (Barberio) Sperm (Spermine) edth Flower (Florence) nte Purath (Phosphorylcholine) itt

Erection of Penis

Applied Aspect:

• cGMP is degraded by phosphodiesterase

• Phosphodiesterase inhibitor (Sildenafil) 
• ↑ cGMP → ↑ NO → Erection

Ejaculation

• Sympathetic (T12-L2 nerve roots).

• Two steps: 
1. Emission (movement of semen into urethra)
2. Ejaculation (Release of semen from urethra).
• Ischiocavernosus contraction →
• External Urethral Sphincter relaxation →
• Bulbospongiosus relaxation

Resolution (Detumescence)

• Endothelin & Noradrenaline → Constriction of arterioles → Resolution.

Male Sex Hormones

Sexual Development

 

 

Normal Sex Development Pathway

• Most Important Gene: SRY (Sex-determining Region Y)
• Located: Distal end of short arm of Y chromosome.
• Testis-determining gene → Produces transcription factors

If SRY is Present: Testis Development

• Sertoli Cells Secrete:
• AMH/MIS:
• Glycoprotein hormone
• Gene for MIS/AMH
• Chromosome 19
• Produced by
• Sertoli cells at 7 weeks
• Granulosa cells of preantral and small antral follicles
• Function: Regression of Mullerian Duct in males.
• Best test for Ovarian reserve
• Done any day
• 1 - 3 = Normal
• High AMH
• > 3: PCOS
• > 3.3: High risk of OHSS
• Good outcome of IVF
• Low AMH
• <1 = Suggestive of POI (Poor Ovarian reserve)
• <0.5 = Diagnostic of POI
• Inhibin B:
• Function: Negative feedback on FSH

• Leydig Cells Secrete:
• First stimulus for testes to secrete testosterone: 
• hCG
• Testosterone:
• At 8 weeks
• Promotes growth of Wolffian Duct (WD) into male internal genitalia:
• Seminal Vesicles (S)
• Ejaculatory Duct (E)
• Epididymis (E)
• Vas Deferens (D)
• 5α-reductase converts Testosterone to DHT (Dihydrotestosterone):
• Leads to masculinization of external genitalia in males.

If SRY is Absent: Ovary Development

• No Sertoli Cells / No Leydig Cells

• No AMH: 
• Mullerian Duct (MD) grows, leading to transformation into female internal genitalia:
• Fallopian Tube
• Uterus
• Cervix
• Upper part of Vagina

• No Testosterone: 
• Wolffian Duct (WD) regresses
  (No masculinization of external genitalia).

Important Notes

• Gene for Testes Formation: SRY gene > SOX gene.

• Mineral needed for SRY gene function: Zinc.

• Spermatogenesis requires both Luteinizing Hormone (LH) and FSH.

Remnants

Mullerian Duct in Males:

• Appendix of testes (hydatid of morgagni)

• Prostatic utricle

Appendix of Testis

• Small pedunculated structure on the upper pole of testis, beneath the tunica vaginalis

• Hydatid of Morgagni

• Remnant of paramesonephric (Müllerian) duct in males

• Homologue of the fallopian tube in females.

• Clinical relevance:
• Can undergo torsion → acute scrotal pain (esp. in children).

Prostatic Utricle

• Müllerian duct remnant

• male homologue of uterus + upper vagina

• Also know as masculine vagina

Exam pearl:

• Müllerian duct remnants → Appendix testis, Prostatic utricle

• Wolffian duct remnants → Appendix epididymis

Gonadal Development

• Genital ridge
• forms gonads
• (at 5 weeks of intrauterine life, testes before ovary).

Development of External Genitalia

• Develops from the same embryological origin in both males and females.

Homologous Organs (Same Embryological Origin)

Ambiguous Genitalia

Definition

• When looking at the external genitalia, the sex of the baby cannot be determined.

• Clinical signs include:
• Clitoromegaly/micropenis
• Labioscrotal swelling

Clinical Approach

• If Testosterone or DHT is present:
• In sufficient quantity in intrauterine life:
• Male external genitalia.
• But in insufficient quantity:
• Ambiguous genitalia.

• If Testosterone or DHT is absent: 
• Female external genitalia.

Phenotype based on Karyotype and Hormone Status

Child Born with Ambiguous Genitalia

• Next step: Physical Examination
• If Gonads are Palpable → (46XY):
• Most common specific cause:
• Partial AIS
• If Gonads are NOT Palpable → (46XX):
• Most common specific cause:
• Congenital Adrenal Hyperplasia (CAH).

Important Considerations (PYQs)

• Barr body (Sex Chromatin)
• Girls go to bar → have bar body; males do not
• Calculation: Number of X chromosomes - 1
• False positive Barr body seen in: Klinefelter's syndrome.
• False negative Barr body seen in: Turner's syndrome.

• Male pseudohermaphrodite:
• Karyotype: 46 XY
• External genitalia: Female
• Causes:
• Complete AIS (m/c)
• Swyer's Syndrome
• 5α reductase deficiency.

• Female pseudohermaphrodite:
• Karyotype: 46 XX
• External genitalia: Ambiguous
• Cause: CAH (Congenital Adrenal Hyperplasia)

Note

• Karyotyping IOC in Ambiguous Genitalia
• First investigation is Physical examination

• Karyotyping is the IOC for sex determination in a child.
• Y (+) → Male: XY (e.g., Klinefelter's 47 XXY)
• Y (-) → Female: XX (e.g., Turner's 45 XO)

Disorders of Sexual Development (DSD) in 46 XX

• Gonadal Problems
• Ovotestis
• Turner's syndrome
• Typically 45 XO
• Characterised by streak ovaries.

• Elevated Androgen Levels During Intra-Uterine Life (IUL) →Leading to Ambiguous Genitalia:
• Androgen drugs taken by pregnant mother.
• CAH
• Aromatase deficiency in placenta.
• Converts maternal androgens to oestrogen.
• Deficiency results in excess androgens.

Ovotestis

• Definition: Presence of both male and female gonads.

• Phenotype:
• Most common: Testis on one side, ovary on the other OR
• Bilateral testicular and ovarian tissue

• Karyotype:
• Most common: 46 XX.
• Can be 46 XX, 46 XY, or mosaic patterns.

• Genital Organ Development:
• Internal Genitalia:
• Ovary side: Mullerian Duct (MD) → female internal genitalia.
• Testis side: Wolffian Duct (WD) → male internal genitalia.
• External Genitalia:
• Typically ambiguous.
• Often resembles male more closely.
• May be identified as male at birth.

• Clinical Presentation:
• About 75% develop breast tissue → gynaecomastia
• Due to oestrogen production from the ovary.
• About 25% may experience menstruation.
• Have uterus

• Diagnosis
• gonadal biopsy

Congenital Adrenal Hyperplasia (CAH)

Enzyme Deficiencies Causing Ambiguous Genitalia

Case discussion

• If an XX karyotype child born with ambiguous genitalia And mother experienced hirsutism during pregnancy.
ANS
→ Aromatase deficiency in the placenta.

Investigations: Precocious Puberty and DSD

• For a child born with Ambiguous Genitalia:
• First step: Physical examination.
• IOC: Karyotyping.
• If gonads are palpable, further checks include:
1. Testosterone.
2. DHT (Dihydrotestosterone).
3. LH/FSH.
4. Pelvic USG.
5. AMH (Anti-Mullerian hormone).
• If gonads are not palpable → m/c CAH
1. 17-OH Progesterone.
2. Testosterone levels.
3. Serum electrolytes.
4. Investigation of Choice (IOC): Karyotyping.
5. Confirmatory: ACTH stimulatory test

For all cases of Precocious Puberty:

• Bone age estimation.

• LH, FSH, and Oestrogen levels:
• To differentiate central (most common) and peripheral types.

• MRI:
• To rule out brain tumours like hamartoma.

• Pelvic USG:
• To rule out oestrogen-secreting ovarian tumours (a peripheral cause).

• TSH:
• To rule out hypothyroidism (another peripheral cause).

For all cases of Heterosexual Precocious Puberty:

• In addition to tests for precocious puberty:
• Testosterone: To rule out androgen-secreting tumours.
• DHEA sulphate: To rule out adrenal tumours secreting androgen.
• 17-OH progesterone: To identify CAH.

Key Fact:

• Androgen Receptor (R) located on the long arm of the X chromosome.

• Normal androgen levels in females: Typically <70 ng.

Case discussion

• If a female has a history of CAH in a previous pregnancy:
• DOC for current pregnancy: Dexamethasone.
• Because it can cross the placenta.

XX Gonadal Sex Reversal Syndrome

• “XX man – SRY sneaks in”
• → 46,XX male due to SRY gene translocation ( m/c/c)
• Y chromosome absent, but SRY gene present (in most cases).
• Opposite of AIS

• Also known as disorder of sex development (DSD).

Clinical Features

• Normal male external genitalia

• Small testes, often azoospermia → infertility

• No Müllerian structures (due to Sertoli cell AMH action)

• May have gynecomastia, eunuchoid habitus

Investigations

• Karyotype: 46,XX

• SRY gene detection: PCR or FISH

• Hormones:
• ↑ LH, FSH
• ↓ Testosterone

• Testicular biopsy: Seminiferous tubule dysgenesis

Disorders of Sexual Development in 46XY

• Female-looking Genitalia:
• Complete Androgen Insensitivity Syndrome (AIS).
• Swyer syndrome.
• 5α reductase deficiency.
• LH receptor defect.

• Ambiguous Genitalia:
• Partial AIS.
• CAH due to:
• 17α hydroxylase deficiency.
• 17, 20-lyase deficiency.
• 3β-HSD deficiency.
• P450 OR deficiency.
• Ovotestis (46XY).

Leydig Cell Hypoplasia

• Autosomal recessive

• 46, XY disorder

• Due to inactivating mutations in LH/hCG receptor

• Leads to failure of normal hormone binding

• Pathophysiology
• ↓ Number or function of Leydig cells
• ↓ Fetal testosterone production
• Results in failure of normal male sexual differentiation

• Effects
• AMH action is normal
• Müllerian duct derivatives are absent
• ↓ Testosterone causes:
• Impaired wolffian duct development
• Failure of testicular descent

• External genitalia:
• Appear female at birth

• Puberty:
• Primary amenorrhea
• Lack of breast development
• Absence of pubic hair

Androgen Insensitivity Syndrome (AIS) vs. Sweyer Syndrome

Complete AIS

• Karyotype: 46XY.

• Gonads: Normal testes.

• Etiopathogenesis: Individuals are completely insensitive to testosterone.

• Sertoli Cells: Normal.
• Leading to AMH-induced Mullerian Duct (MD) regression.

• Leydig Cells: Normal.
• Producing testosterone.

• Internal Genital Organs: Absent.
• Testosterone resistance leads to Wolffian Duct (WD) regression.

• Uterus: Absent.

• External Genital Organs: Female.
• Due to DHT resistance.
• Blind ending vagina can be seen

• At Puberty: Testosterone is aromatised into oestrogen.

• Breast Fully developed (Tanner stage 4 or 5).
• Due to oestrogen.

• Pubic Hair: Scanty (Tanner stage 1 or 2).
• Due to androgen resistance.

• Presentation:
• Primary amenorrhoea +
• Bilateral inguinal hernia.
• Due to undescended testes.
• Carry an increased risk of malignancy.
• Well developed Breast with No/less pubic hair

• Hormonal Profile for AIS:
• LH is elevated (similar to PCOS).
• FSH is normal.
• Androgens are elevated (corresponding to male androgen levels).

• Management (to retain female phenotype):
• Gonadectomy is performed between 14-16 years.
• Allows for full breast development.
• Dysgenetic or Undescended Testes:
• Carry an increased chance of malignancy.
• Necessitating gonadectomy.
• Most common gonadal tumour: Gonadoblastoma.
• Most common gonadal malignancy: Dysgerminoma/seminoma.
• Comparison note: Streak Ovaries:
• Unlike dysgenetic testes, streak ovaries do not become malignant.
• No gonadectomy is required.
• Oestrogen replacement therapy is crucial.
• Vaginoplasty is also indicated.
• Timing: Ideally done just before or just after marriage.
• Techniques:
• McIndoe technique or Laparoscopic Vecchietti technique commonly used.

Differential Diagnosis for AIS (Absent Uterus):

1. Mullerian agenesis (Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome).

2. Partial AIS
• Only difference is in Partial AIS → Ambiguous genitalia (Clitoromegaly or labioscrotal swelling) present

Swyer Syndrome

 

• Sertoli Cells: Dysgenetic.
• Meaning AMH is absent.
• Leading to MD growth.
• Internal Genital Organs: Female.
• Uterus: Present.

• Karyotype: 46XY.

• Gonads: Dysgenetic testes.

• Complete Gondal Dysgenesis

• Etiopathogenesis:
• 20% → Mutation
• Point mutation > SRY gene deletion
• 80% normal SRY gene

• At Puberty:
• Testosterone is absent due to dysgenetic testes.

• Leydig Cells: Dysgenetic.
• Thus testosterone absent.
• Leading to WD regression.

• External Genital Organs: Female.

• Breast Development: Absent (Tanner stage 1)

• Pubic Hair: Scanty or absent.

• Hormonal Profile:
• Both LH and FSH are elevated.
• Androgens are decreased.

• Management:
• Gonadectomy is performed at the time of diagnosis.
• Oestrogen replacement therapy for one year for breast development.
• Followed by life-long oestrogen + progesterone.

D/D for AIS (Absent uterus)

Mullerian agenesis:
(Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome)

• Karyotype: 46XX.
• Karyotyping is the IOC to rule out AIS.

• Anomalies:
1. Both Mullerian ducts are absent.
• Meaning fallopian tubes, uterus, cervix, and upper vagina are absent.
2. Associated with renal anomalies.
• Requiring an IVP.
3. May also present with skeletal anomalies.

• Ovaries: Normal.
• With normal ovulation and oestrogen production.

• Breast and Pubic/Axillary Hair Development: Normal (Tanner stage 4/5).
• Due to normal oestrogen production.

• Hormonal Profile: LH, FSH, and oestrogen levels are all normal.

• Symptoms: Primary amenorrhoea and coital difficulties.

5α Reductase Deficiency

• Function: Enzyme converts testosterone into DHT (Dihydrotestosterone).

• Male child born with female external genitalia and no pubic hair

Features:

• Genotype: 46 XY.

• Gonads: Normal, but undescended testes.

• Sertoli Cells: Normal.
• Leading to AMH-induced MD regression.

• Leydig Cells: Normal.
• Producing testosterone.
• Promotes male internal organ growth.

• External Genitalia: Female at birth.
• Due to absence of DHT.
• Note that undescended testes are a feature.

• Pubic/Axillary Hair: Scanty.
• Due to absent DHT.

• At Puberty (Virilisation occurs):
• Development of secondary male sexual characteristics:
• Deepening of voice.
• Increased muscle mass.
• Clitoromegaly (absent at birth).
• Breast development is absent
• Aromatization to estrogen is not enough to dominate
• because testosterone effect is active
• Hirsutism.

• Hormonal Profile: FSH, LH, and Testosterone levels are typically normal.

Partial AIS vs. 5α Reductase Deficiency