Distal spinal muscular atrophy type 2 (DSMA2), also known as Jerash type distal hereditary motor neuropathy (HMN-J) — is a very rare childhood-onset genetic disorder characterised by progressive muscle wasting affecting lower and subsequently upper limbs. The disorder has been described in Arab inhabitants of Jerash region in Jordan as well as in a Chinese family.

The condition is linked to a genetic mutation in the "SIGMAR1" gene on chromosome 19 (locus 19p13.3) and is likely inherited in an autosomal recessive manner.

Distal hereditary motor neuronopathies (distal HMN, dHMN), sometimes also called distal hereditary motor neuropathies, are a genetically and clinically heterogeneous group of motor neuron diseases that result from genetic mutations in various genes and are characterized by degeneration and loss of motor neuron cells in the anterior horn of the spinal cord and subsequent muscle atrophy.

Although they can hardly be distinguished from hereditary motor and sensory neuropathies on the clinical level, dHMNs are considered a separate class of disorders.

In 1993, A. E. Hardnig proposed to classify hereditary motor neuropathies into seven groups based on age at onset, mode of inheritance, and presence of additional features. This initial classification has since been widely adopted and expanded and currently looks as follows:

Note: Acronym "HMN" is also used interchangeably with "DHMN".

Kabuki syndrome (also previously known as kabuki makeup syndrome, KMS or Niikawa–Kuroki Syndrome), is a pediatric congenital disorder of suspected genetic origin with multiple congenital anomalies and intellectual disabilities. It is quite rare, affecting roughly one in 32,000 births. It was identified and described in 1981 by two Japanese groups, led by the scientists Norio Niikawa and Yoshikazu Kuroki. It is named kabuki syndrome because of the facial resemblance of affected individuals to stage makeup used in kabuki, a Japanese traditional theatrical form.

Via a photo shown on a Facebook page, the mother of a child previously diagnosed with this condition recognised the symptoms and reported them to the family involved, resulting in an immediate diagnosis that medical professionals had overlooked in all earlier consultations.

The highest rate of neurological problems of single suture synostosis are seen in patients with trigonocephaly. Surgery is performed generally before the age of one because of claims of better intellectual outcome. Seemingly surgery does not influence the high incidence of neurodevelopment problems in patients with metopic synostosis. Neurological disorders such as ADHD, ASD, ODD and CD are seen in patients with trigonocephaly. These disorders are usually also associated with decreased IQ. The presence of ADHD, ASD and ODD is higher in cases with an IQ below 85. This is not the case with CD which showed an insignificant increase at an IQ below 85.

The treatments of kabuki syndrome are still being developed due to its genetic nature. The first step to treatment is diagnosis. After diagnosis, the treatment of medical conditions can often be treated by medical intervention. There are also options in psychotherapy for young children with this disorder, as well as the family of the child. Genetic counseling is available as a preventative treatment for kabuki syndrome because it can be inherited and expressed by only having one copy of the mutated gene.

Pectus malformations are common; about 1 in 400 people have a pectus disorder.

Pectus carinatum is rarer than pectus excavatum, another pectus disorder, occurring in only about 20% of people with pectus malformations. About four out of five patients are males.

After adolescence, some men and women use bodybuilding as a means to hide their malformation. Some women find that their breasts, if large enough, serve the same purpose. Some plastic surgeons perform breast augmentation to disguise mild to moderate cases in women. Bodybuilding is suggested for people with symmetrical pectus carinatum.

Though there is no treatment for Cone dystrophy, certain supplements may help in delaying the progression of the disease.

The beta-carotenoids, lutein and zeaxanthin, have been evidenced to reduce the risk of developing age related macular degeneration (AMD), and may therefore provide similar benefits to Cone dystrophy sufferers.

Consuming omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) has been correlated with a reduced progression of early AMD, and in conjunction with low glycemic index foods, with reduced progression of advanced AMD, and may therefore delay the progression of cone dystrophy.

Penile fracture is a relatively uncommon clinical condition. Vaginal intercourse and aggressive masturbation are the most common causes. A 2014 study of accident and emergency records at three hospitals in Campinas, Brazil, showed that woman on top positions caused the greatest risk with the missionary position being the safest. The research conjectured that when a woman is on top, she usually controls the movement and her entire body weight lands on the erect penis. She is not able to interrupt movement when the penis suffers a misaligned penetration. Conversely, when the man is controlling the movement, he has better chances of stopping the penetration thrusts in response to pain, minimizing harm to himself.

The practice of "taqaandan" (also "taghaandan") also puts men at risk of penile fracture. Taqaandan, which comes from a Kurdish word meaning "to click", involves bending the top part of the erect penis while holding the lower part of the shaft in place, until a click is heard and felt. Taqaandan is said to be painless and has been compared to cracking one's knuckles, but the practice of taqaandan has led to an increase in the prevalence of penile fractures in western Iran. Taqaandan may be performed to achieve detumescence.

Penile fracture is a medical emergency, and emergency surgical repair is the usual treatment. Delay in seeking treatment increases the complication rate. Non-surgical approaches result in 10–50% complication rates including erectile dysfunction, permanent penile curvature, damage to the urethra and pain during sexual intercourse, while operatively treated patients experience an 11% complication rate.

In some cases, retrograde urethrogram may be performed to rule out concurrent urethral injury.

At least one type of autosomal dominant cone-rod dystrophy is caused by mutations in the guanylate cyclase 2D gene (GUCY2D) on chromosome 17.

A neutral spine or good posture refers to the "three natural curves [that] are present in a healthy spine." Looking directly at the front or back of the body, the 33 vertebrae in the spinal column should appear completely vertical. From a side view, the cervical (neck) region of the spine (C1-C7) is bent inward, the thoracic (upper back) region (T1-T12) bends outward, and the lumbar (lower back) region (L1-L5) bends inward. The sacrum (tailbone area) (S1-S5 fused) and coccyx (on average 4 fused) rest between the pelvic bones. A neutral pelvis indicates the anterior superior iliac spines and pubic symphysis fall in the same vertical line.

Scoliosis is well established and even evaluated at an early age. It is typically quantified using the standardized Cobb angle method. This method consists of measuring the degree of deformity by the angle between two successive vertebrae. The Cobb method was accepted by the Scoliosis Research Society (SRS) in 1966. It serves as the standard method for quantification of scoliosis deformities. Sagittal plane posture aberrations such as cervical and lumbar lordosis and thoracic kyphosis have yet to be quantified due to considerable inter-individual variability in normal sagittal curvature. The Cobb method was also one of the first techniques used to quantify sagittal deformity. As a 2D measurement technique it has limitations and new techniques are being proposed for measurement of these curvatures. Most recently, 3D imaging techniques using computed tomography (CT) and magnetic resonance (MR) have been attempted. These techniques are promising but lack the reliability and validity necessary to be used as a reference for clinical purposes.

Posture assessment has also become quite popular in many practical environments like the personal training and sports conditioning settings. The need for reliable methods of posture assessment as a screening tool is warranted. Current available programs such as those through the National Posture Institute (NPI) and Posture Print are recommended for the practical setting but cost close to $1000 and are clearly a profiteering scam by individuals not at all concerned with human well-being.

Chronic deviations from neutral spine lead to improper posture, increased stress on the back and causes discomfort and damage. People who sit for long hours on the job are susceptible to a number of misalignments.

"Neutral spine" is ideally maintained while sitting, standing, and sleeping.

Although the incidence of underage drinking is still significant, government, university and national statistics have confirmed that alcohol use and binge drinking among high school students has declined steadily over the past three decades, and continues to decline annually. According to a United States Substance Abuse and Mental Health Services Administration study involving 30,000 youths aged 12 to 20 years old, between 2002 and 2013 the percentage of underage drinkers declined from 28.8% to 22.7%. Underage binge drinkers decreased 19.3% to 14.2%. A December 2014 study performed by the University of Michigan also found that 75% of senior high school students disapproved of drinking excessively on the weekends. Alcohol still proved to be the favored substance of abuse among American youths however, with tobacco and illicit drugs following in rank.

Stereoblindness (also stereo blindness) is the inability to see in 3D using stereopsis, or stereo vision, resulting in an inability to perceive stereoscopic depth by combining and comparing images from the two eyes.

Individuals with only one functioning eye always have this condition; the condition also results when two eyes do not function together properly.

Stereoblind persons with two healthy eyes do employ binocular vision to some extent, albeit less than persons with normally developed eyesight. This was shown in a study in which stereoblind subjects were posed with the task of judging the direction of rotation of a simulated transparent cylinder: the subjects performed better when using two eyes than when using their preferred eye. They appeared to judge the direction of rotation from the images in each eye separately and then to combine these judgments, rather than relying on differences between the images in the two eyes. Also, purely binocular motion stimuli appear to influence stereoblind persons' sensation of self-motion. Furthermore, in some cases each eye can contribute to peripheral vision for one side of the field of view (see also monofixation syndrome).

Genetically informed studies of the personality characteristics typical of individuals with psychopathy have found moderate genetic (as well as non-genetic) influences. On the PPI, fearless dominance and impulsive antisociality were similarly influenced by genetic factors and uncorrelated with each other. Genetic factors may generally influence the development of psychopathy while environmental factors affect the specific expression of the traits that predominate. A study on a large group of children found more than 60% heritability for "callous-unemotional traits" and that conduct problems among children with these traits had a higher heritability than among children without these traits.

Alcohol consumption by youth in the United States of America is an umbrella term for alcohol consumption by individuals under the age of 21 in the country.

Although the minimum legal age to purchase alcohol is 21 in all states (see National Minimum Drinking Age Act), the legal details vary greatly. While a few states completely ban alcohol usage for people under 21, the majority have exceptions that permit consumption.

Underage drinking has become an activity primarily done behind closed doors. Typically, underage drinkers hide their alcohol consumption by drinking quickly before they go out, which is often referred to as pregaming or pre-partying. Brittany Levine explained in her article "Pre-Gaming" in USA Today that "of all drinking events involving pre-partying, 80% involved additional drinking afterward." Those who oppose a complete ban on underage drinking argue that it is important that minors be introduced to alcohol in a controlled environment, so that supervision and guidance might occur instead of experimentation. Some parents are willing to provide alcohol for their children if they drink it in a controlled environment. Furnishing alcohol to one's own children is permitted in 31 states, while it's illegal to do so for other people's children in all fifty states. Social host ordinances have been enacted in a number of jurisdictions to attempt to limit the parties where adults may permit minors to drink. Social host laws or ordinances have proliferated in the last ten years because it has been too difficult for law enforcement to prove which adults furnished or served alcohol to minors in their own home, so it permits them to cite or arrest the adult who has control of the premises.

A study by Farrington of a sample of London males followed between age 8 and 48 included studying which factors scored 10 or more on the PCL:SV at age 48. The strongest factors included having a convicted parent, being physically neglected, low involvement of the father with the boy, low family income, and coming from a disrupted family. Other significant factors included poor supervision, harsh discipline, large family size, delinquent sibling, young mother, depressed mother, low social class, and poor housing. There has also been association between psychopathy and detrimental treatment by peers. However, it is difficult to determine the extent of an environmental influence on the development of psychopathy because of evidence of its strong heritability.

Some types of BDSM play include, but are not limited to:

- Animal roleplay

- Bondage

- Breast torture

- Cock and ball torture (CBT)

- Erotic electrostimulation

- Edgeplay

- Flogging

- Golden showers (urinating)

- Human furniture

- Japanese bondage

- Medical play

- Paraphilic infantilism

- Predicament bondage

- Pussy torture

- Sexual roleplay

- Spanking

- Suspension

- Torture

- Tickle torture

- Wax play

Constructional apraxia is characterized by an inability or difficulty to build, assemble, or draw objects. Apraxia is a neurological disorder in which people are unable to perform tasks or movements even though they understand the task, are willing to complete it, and have the physical ability to perform the movements. Constructional apraxia may be caused by lesions in the parietal lobe following stroke or it may serve as an indicator for Alzheimer's disease.

Research has shown that paraphilias are rarely observed in women. However, there have been some studies on females with paraphilias. Sexual masochism has been found to be the most commonly observed paraphilia in women, with approximately 1 in 20 cases of sexual masochism being female.

Many acknowledge the scarcity of research on female paraphilias. The majority of paraphilia studies are conducted on people who have been convicted of sex crimes. Since the number of male convicted sex offenders far exceeds the number of female convicted sex offenders, research on paraphilic behavior in women is consequently lacking. Some researchers argue that an underrepresentation exists concerning pedophilia in females. Due to the low number of women in studies on pedophilia, most studies are based from "exclusively male samples". This likely underrepresentation may also be attributable to a "societal tendency to dismiss the negative impact of sexual relationships between young boys and adult women". Michele Elliott has done extensive research on child sexual abuse committed by females, publishing the book "Female Sexual Abuse of Children: The Last Taboo" in an attempt to challenge the gender-biased discourse surrounding sex crimes. John Hunsley states that physiological limitations in the study of female sexuality must also be acknowledged when considering research on paraphilias. He states that while a man's sexual arousal can be directly measured from his erection (see penile plethysmograph), a woman's sexual arousal cannot be measured as clearly (see vaginal photoplethysmograph), and therefore research concerning female sexuality is rarely as conclusive as research on men.

The prevalence of pedophilia in the general population is not known, but is estimated to be lower than 5% among adult men. Less is known about the prevalence of pedophilia in women, but there are case reports of women with strong sexual fantasies and urges towards children. Most sexual offenders against children are male. Females may account for 0.4% to 4% of convicted sexual offenders, and one study estimates a 10 to 1 ratio of male-to-female child molesters. The true number of female child molesters may be underrepresented by available estimates, for reasons including a "societal tendency to dismiss the negative impact of sexual relationships between young boys and adult women, as well as women's greater access to very young children who cannot report their abuse", among other explanations.

The term "pedophile" is commonly used by the public to describe all child sexual abuse offenders. This usage is considered problematic by researchers, because many child molesters do not have a strong sexual interest in prepubescent children, and are consequently not pedophiles. There are motives for child sexual abuse that are unrelated to pedophilia, such as stress, marital problems, the unavailability of an adult partner, general anti-social tendencies, high sex drive, or alcohol use. As child sexual abuse is not automatically an indicator that its perpetrator is a pedophile, offenders can be separated into two types: pedophilic and non-pedophilic (or preferential and situational). Estimates for the rate of pedophilia in detected child molesters generally range between 25% and 50%. A 2006 study found that 35% of its sample of child molesters were pedophilic. Pedophilia appears to be less common in incest offenders, especially fathers and step-fathers. According to a U.S. study on 2429 adult male sex offenders who were categorized as "pedophiles", only 7% identified themselves as exclusive; indicating that many or most child sexual abusers may fall into the non-exclusive category.

Some pedophiles do not molest children. Little is known about this population because most studies of pedophilia use criminal or clinical samples, which may not be representative of pedophiles in general. Researcher Michael Seto suggests that pedophiles who commit child sexual abuse do so because of other anti-social traits in addition to their sexual attraction. He states that pedophiles who are "reflective, sensitive to the feelings of others, averse to risk, abstain from alcohol or drug use, and endorse attitudes and beliefs supportive of norms and the laws" may be unlikely to abuse children. A 2015 study indicates that pedophiles who molested children are neurologically distinct from non-offending pedophiles. The pedophilic molesters had neurological deficits suggestive of disruptions in inhibitory regions of the brain, while non-offending pedophiles had no such deficits.

According to Abel, Mittleman, and Becker (1985) and Ward "et al." (1995), there are generally large distinctions between the characteristics of pedophilic and non-pedophilic molesters. They state that non-pedophilic offenders tend to offend at times of stress; have a later onset of offending; and have fewer, often familial, victims, while pedophilic offenders often start offending at an early age; often have a larger number of victims who are frequently extrafamilial; are more inwardly driven to offend; and have values or beliefs that strongly support an offense lifestyle. One study found that pedophilic molesters had a median of 1.3 victims for those with girl victims and 4.4 for those with boy victims. Child molesters, pedophilic or not, employ a variety of methods to gain sexual access to children. Some groom their victims into compliance with attention and gifts, while others use threats, alcohol or drugs, or physical force.

A key deficit in constructional apraxia patients is the inability to correctly copy or draw an image. There are qualitative differences between patients with left hemisphere damage, right hemisphere damage, and Alzheimer's Disease.