Using a brain-imaging technique, Swedish researchers have shown that homosexual and heterosexual males brains respond in different ways to two odors that may be involved in sexual arousal, and that homosexual men respond in the same way as heterosexual women, though it could not be determined whether this was cause or effect. When the study was expanded to include lesbian women, the results were consistent with previous findings – meaning that lesbian women were not as responsive to male-identified odors, while responding to female odors in a similar way as heterosexual males. According to the researchers, this research suggests a possible role for human pheromones in the biological basis of sexual orientation. Genes affecting body odor
MHC
Body odor is largely influenced by major histocompatibility complex (MHC) molecules. These are genetically determined and play an important role in immunity of the organism. The vomeronasal organ contains cells sensitive to MHC molecules in a genotype-specific way.Experiments on animals and volunteers have shown that potential sexual partners tend to be perceived more attractive if their MHC composition is substantially different. Married couples are more different regarding MHC genes than would be expected by chance. This behavior pattern promotes variability of the immune system of individuals in the population, thus making the population more robust against new diseases. Another reason may be to prevent inbreeding. ABCC11
The ABCC11 gene determines axillary body odor and the type of earwax.
Sponastrime dysplasia is a rare condition characterised by facial and skeletal abnormalities. Signs and symptoms
The main features of this condition are evident in skeleton and face.Facial features:

Macrocephaly
Frontal bossing
Midface hypoplasia
Depressed nasal root
Small upturned nose
PrognathismSkeletal features:

Shortened limbs (more pronounced in lower limbs)
Short stature
Progressive coxa varaOn X ray:

Abnormal vertebral bodies (particularly in the lumbar region)
Avascular necrosis of the capital femoral epiphyses
Striated metaphyses
Generalized mild osteoporosis
Delayed ossification of the carpal bonesOther associated conditions:
These are variably present
Cataracts
Hypogammaglobulinemia
Intellectual disability
Short dental roots
Subglottic stenosis
Tracheobronchomalacia

Genetics
This condition has been associated with mutations in the Tonsoku-like, DNA repair protein (TONSL) gene. This gene is located on the long arm of chromosome 8 (8q24.3). This gene is also known as NFKBIL2. Pathopysiology
This is not understood. It appears that the TONSL gene product is involved in genome repair. Diagnosis
This can be suspected when the usual facial and skeletal features are present. It is confirmed by sequencing the TONSL gene. Differential diagnosis
Short limbed dwarfism syndrome in association with immunodeficiency. Treatment
There is no specific treatment for this condition. Management is supportive. Epidemiology
This condition is considered to be rare with less than 100 cases reported in the literature. History
This condition was first described in 1983. == References ==