Given below are statements about the Kallmann syndrome. A. It is a condition of hypogonadotropic hypogonadism. B. There is a loss of sense of smell in such individuals. C. This syndrome is most common in women. D. It happens due to mutation of the KALIG1 gene on X-chromosome that codes for an adhesion molecule necessary for the normal development of the gustatory nerve. Which one of the following options has the combination of all correct statements?
A and B
Kallmann Syndrome Explained
Kallmann syndrome is a genetic condition that affects development, specifically causing a combination of hormonal deficiency and a reduced or absent sense of smell.
Let's examine each statement provided about Kallmann syndrome:
- Statement A: It is a condition of hypogonadotropic hypogonadism.
This statement is correct. Hypogonadotropic hypogonadism means the gonads (testes in males, ovaries in females) produce little or no sex hormones (like testosterone or estrogen) because they are not stimulated properly by the pituitary gland. The pituitary gland doesn't produce enough of the gonadotropin hormones (luteinizing hormone - LH, and follicle-stimulating hormone - FSH), which is due to a problem with the brain's production of gonadotropin-releasing hormone (GnRH). Kallmann syndrome is a classic example of this condition.
- Statement B: There is a loss of sense of smell in such individuals.
This statement is also correct. Anosmia (complete loss of smell) or hyposmia (reduced sense of smell) is a defining characteristic of Kallmann syndrome. This is because the olfactory neurons (smell nerves) and the GnRH-producing neurons fail to migrate correctly from the nose to the brain during development.
- Statement C: This syndrome is most common in women.
This statement is incorrect. Kallmann syndrome is significantly more common in men than in women. The exact ratio varies depending on studies, but it is typically reported to be 2 to 5 times more frequent in males.
- Statement D: It happens due to mutation of the KALIG1 gene on X-chromosome that codes for an adhesion molecule necessary for the normal development of the gustatory nerve.
This statement contains several inaccuracies. While mutations in genes on the X-chromosome, such as KAL1 (sometimes referred to in older literature or related contexts), can cause X-linked Kallmann syndrome, the gene name provided (KALIG1) is slightly off (the primary gene is KAL1). More importantly, the gene codes for an adhesion molecule (anosmin-1) necessary for the migration of GnRH neurons and olfactory neurons, not the gustatory nerve (which is involved in taste). Therefore, this statement is incorrect.
Based on the analysis, statements A and B are correct descriptions of Kallmann syndrome.
Important Questions from System Physiology Animal
Which one of the following synaptic vesicles (as observed under transmission electron microscope) contains catecholamines?
Blood hemostasis is the interplay of several intrinsic and extrinsic factors. Deficiency of some of the blood clotting factors and their clinical manifestations are listed below.
Factors
Manifestations
A.
V
i.
Hageman trait
B.
VII
ii.
Hypoconvertemia
C.
IX
iii.
Hemophilia B
D.
XII
iv.
Parahemophilia
Which one of the following options represents all correct matches?
Aldosterone is synthesized exclusively in zona glomerulosa due to the presence of _________ enzyme in addition to a dehydrogenase.
How much hemoglobin is present approximately in each normal human red blood cell?
The sensory nerve fibers (Column X) and the sensory receptors connected to different sensory nerves (Column Y) are given below.
Column X
Column Y
Sensory nerve fibre
Sensory receptor
A.
la
i.
Muscle spindle, flower spray ending
B.
Ib
ii.
Pain and cold receptor
C.
II
iii.
Muscle spindle, annulo-spiral ending
D.
III
iv.
Golgi tendon organ
Which of the following options represents the correct match between column X and column Y?
