MID - Cytogenetic Infertility (Quiz)

Infertility

The inability to conceive after one year of unprotected intercourse.

Azoospermia

The absence of sperm in semen.

Severe Oligospermia

A significantly low sperm count in semen.

AZF region

The region on the Y chromosome critical for sperm production, where deletions can cause infertility.

Klinefelter’s syndrome

A numerical chromosomal abnormality in males characterized by a 47, XXY karyotype.

47, XYY syndrome

A numerical chromosomal abnormality in males characterized by a 47, XYY karyotype.

Turner syndrome

A numerical chromosomal abnormality in females characterized by a 45, X karyotype.

Inversion

A type of structural chromosomal abnormality where a segment of a chromosome is inverted.

Robertsonian translocation

A structural chromosomal abnormality involving the exchange of genetic material between non-homologous chromosomes, common in infertile couples.

Marker chromosome

Very small, unidentified additional chromosomes that can be associated with infertility.

10-15%

The approximate percentage of couples worldwide who experience infertility.

Short arm

Incorrect option; not relevant for male infertility.

Centromere

Incorrect option; not relevant for male infertility.

Telomere

Incorrect option; not relevant for male infertility.

c) Non-disjunction of the X chromosome during meiosis

The cause of Klinefelter’s syndrome (47, XXY).

a) 45, X (Turner syndrome)

The numerical chromosomal abnormality in females associated with early onset of menopause.

b) t(13q14q)

The most common Robertsonian translocation observed in infertile males.

c) Absence or severe reduction in sperm count

The primary effect of Y chromosome microdeletions on male fertility.

b) Obstructive azoospermia due to congenital absence of the vas deferens

Effect of CFTR gene mutations that can lead to male infertility.

c) Turner syndrome

Chromosomal abnormality characterized by loss of an X chromosome, leading to infertility in females.

b) Production of abnormal gametes during meiosis

Inversions in chromosomes increase the risk of infertility because they can lead to this.

c) Sterility due to spermatogenic arrest

Result of Down syndrome (Trisomy 21) in males.

unprotected

Infertility is defined as the failure to conceive after one year of unprotected intercourse.

health

The World Health Organization considers infertility a human health problem of global concern.

AZF

Deletions in the AZF region on the Y chromosome can lead to azoospermia.

47, XXY

Males with Klinefelter’s syndrome typically have a karyotype of 47, XXY.

Y

The 47, XYY syndrome in males arises due to non-disjunction of the Y chromosome in paternal meiosis II.

menopause

Females with a 47, XXX karyotype may experience an early onset of menopause around the age of 30.

X

Turner syndrome is characterized by a loss of the X chromosome.

structural

Robertsonian translocations are common structural chromosomal rearrangements seen in the general population.

13, 14

The most common Robertsonian translocation involves chromosomes 13 and 14.

marker

Carriers of marker chromosomes are at risk of infertility because of meiotic arrest and instability.

True

Infertility affects approximately 50 to 80 million people worldwide.

False

Male infertility is solely caused by genetic factors.

True

Deletions in all three sub-regions of the AZF region on the Y chromosome invariably lead to azoospermia.

False

Individuals with Klinefelter’s syndrome are typically phenotypically female.

False

Males with the 47, XYY karyotype usually have fertility problems.

False

Females with Turner syndrome are typically fertile and can conceive spontaneously.

False

Robertsonian translocations always result in infertility in the carriers.

False

Balanced reciprocal translocations do not usually affect fertility.

False

Mutations in the CFTR gene only affect the respiratory system and not male fertility.

True

Cytogenetic analysis is a crucial tool in the diagnosis and management of infertility.

karyotype analysis and Y chromosome microdeletion testing

Initial cytogenetic test recommended for a male partner with low sperm count.

infertile

Most females with Turner syndrome are infertile due to a rapid loss of eggs within the ovaries.

reduced testosterone levels and impaired sperm production

Potential impact on fertility for a male with Klinefelter’s syndrome.

karyotype analysis

Cytogenetic test to check for balanced chromosomal rearrangements after multiple miscarriages.

CFTR gene mutations

Specific gene mutation often associated with obstructive azoospermia.