Preferred Label : Musk, inability to smell;
Type : Phenotype or locus, molecular basis unknown;
Description : Whissell-Buechy and Amoore (1973) suggested that inability to smell musk is an autosomal
recessive trait. Musk pentadecalactone could not be smelled by about 7% of Caucasians,
but this deficiency was not found in any Blacks. The authors stated that there were
27 discrete anosmias. Kalmus and Seedburgh (1975) confirmed the work of Whissell-Buechy
and Amoore (1973). They also found a highly correlated bimodality (presumed to be
caused by the absence or inactivity of certain receptor sites) for another structurally
different substance, musk ambrette. The thresholds for musk ketone showed no bimodality
and a low correlation with the thresholds for the other two musks. The olfactory system
has to discriminate between a large number of low molecular weight compounds in the
air. The elucidation of how this is done is a challenge comparable to discovering
how the immune system works. Odorant receptors appear to activate a cyclic nucleotide
enzyme cascade, including a GTP-binding protein, analogous with the processes of hormone,
neurotransmitter and visual reception (Lancet and Pace, 1987). Odorants may excite
olfactory receptor cells by activating ion channels. This, in turn, may generate patterns
of different neuronal activity which are relayed to the CNS and decoded as distinct
odors (Anholt, et al. 1987). The guanine nucleotide-binding proteins (G or N proteins)
are ubiquitous features of signal transduction mechanisms involving control of intracellular
calcium and second messengers, regulation of cell growth, gating of ion channels,
olfaction, vision, and possibly other sensory systems. Possibly because of their key
role in signal transduction, G proteins have been singled out as targets by toxins
from several types of bacteria, e.g., those causing diphtheria, cholera, and pertussis.
These toxins have proved valuable in identifying the function of the different G proteins
(Dolphin, 1987). It is possible that specific anosmia or 'smell blindness' in the
olfactory system is analogous to colorblindness in vision, where unequal crossing
over between the highly homologous receptors within a cluster during gametogenesis
results in the formation of new hybrid receptors and/or the deletion of receptor genes
(Reed, 1996). The inheritance of specific anosmia to pentadecalactone as a recessive
is consistent with mutation or loss of the receptor gene for this particular odorant.
*FIELD* SA Anholt (1987) *FIELD* RF 1. Anholt, R. R. H.: Primary events in olfactory
reception. Trends Biochem. 12: 58-62, 1987. 2. Dolphin, A. C.: Nucleotide binding
proteins in signal transduction and disease. Trends Neurosci. 10: 53-57, 1987. 3.
Kalmus, H.; Seedburgh, D.: Correlated odour threshold bimodality of two out of three
synthetic musks. Ann. Hum. Genet. 38: 495-499, 1975. 4. Lancet, D.; Pace, U.: The
molecular basis of odor recognition. Trends Biochem. 12: 63-66, 1987. 5. Reed, R.
R.: Genetic approaches to mammalian olfaction. Cold Spring Harbor Symp. Quant. Biol.
61: 165-172, 1996. 6. Whissell-Buechy, D.; Amoore, J. E.: Odour-blindness to musk:
simple recessive inheritance. Nature 242: 271-273, 1973. *FIELD* CS Autosomal recessive;
Inheritance : Autosomal recessive;
Prefixed ID : %254150;
Origin ID : 254150;
UMLS CUI : C1850807;
Currated CISMeF NLP mapping
- HPO term(s)
- Semantic type(s)
- UMLS correspondences (same concept)
