Although the last days of the menstrual cycle are marked by a constant testosterone level, womens libido may get a boost as a result of the thickening of the uterine lining which stimulates nerve endings and makes a woman feel aroused. Also, during these days, estrogen levels decline, resulting in a decrease of natural lubrication. Although some specialists disagree with this theory, menopause is still considered by the majority a factor that can cause decreased sexual desire in women. The levels of estrogen decrease at menopause and this usually causes a lower interest in sex and vaginal dryness which makes sex painful. However, the levels of testosterone increase at menopause and this may be why some women may experience a contrary effect of an increased libido. Psychological and social factors
Certain psychological or social factors can reduce the desire for sex. These factors can include lack of privacy or intimacy, stress or fatigue, distraction, or depression. Environmental stress, such as prolonged exposure to elevated sound levels or bright light, can also affect libido. Other causes include experience of sexual abuse, assault, trauma, or neglect, body image issues, and anxiety about engaging in sexual activity.Individuals with PTSD may find themselves with reduced sexual desire. Struggling to find pleasure, as well as having trust issues, many with PTSD experience feelings of vulnerability, rage and anger, and emotional shutdowns, which have been shown to inhibit sexual desire in those with PTSD. Reduced sex drive may also be present in trauma victims due to issues arising in sexual function.
SHFM is a heterogeneous condition caused by abnormalities at one of multiple loci, including SHFM1 (SHFM1 at 7q21-q22), SHFM2 (Xq26), SHFM3 (FBXW4/DACTYLIN at 10q24), SHFM4 (TP63 at 3q27), and SHFM5 (DLX1 and DLX 2 at 2q31). SHFM3 is unique in that it is caused by submicroscopic tandem chromosome duplications of FBXW4/DACTYLIN. SHFM3 is considered isolated ectrodactyly and does not show a mutation of the tp63 gene. Presentation
Ectrodactyly can be caused by various changes to 7q. When 7q is altered by a deletion or a translocation, ectrodactyly can sometimes be associated with hearing loss. Ectrodactyly, or Split hand/split foot malformation (SHFM) type 1 is the only form of split hand/ malformation associated with sensorineural hearing loss. Genetics
A large number of human gene defects can cause ectrodactyly. The most common mode of inheritance is autosomal dominant with reduced penetrance, while autosomal recessive and X-linked forms occur more rarely. Ectrodactyly can also be caused by a duplication on 10q24. Detailed studies of a number of mouse models for ectrodactyly have also revealed that a failure to maintain median apical ectodermal ridge (AER) signalling can be the main pathogenic mechanism in triggering this abnormality.A number of factors make the identification of the genetic defects underlying human ectrodactyly a complicated process: the limited number of families linked to each split hand/foot malformation (SHFM) locus, the large number of morphogens involved in limb development, the complex interactions between these morphogens, the involvement of modifier genes, and the presumed involvement of multiple gene or long-range regulatory elements in some cases of ectrodactyly.