Two people are never the same, due to the different ways our genomes are expressed. But sometimes these differences can lead to genetic mutations which are extremely rare, and sometimes debilitating. Many people who are suffering from these mutations were labeled freaks, but they are part of the broad spectrum of genetic variations in our species. Here is a list of 10 most unusual genetic mutations which are identified in humans:
1. Marfan Syndrome
Marfan syndrome is a disorder of the connective tissues. But it’s more renowned for the way it causes bones to overgrow and create loose joints. People with Marfan Syndrome tend to have long and thin arms and legs. Overgrown ribs are the reason that causes chest bone to bend inward or push outward. Spinal curvature is another problem. There are famous people with Marfan syndrome, which include Javier Botet, Sergei Rachmaninoff, Robert Johnson, and Bradford Cox of Deerhunter/Atlas Sound fame.
2. Mermaid Syndrome
Mermaid Syndrome is a rare congenital deformity in which the legs are fused together, giving them the appearance of a mermaid’s tail. This condition is found in approximately one out of every 100,000 live births. It is usually fatal within a day or two of birth because of complications associated with abnormal kidney and urinary bladder development and function. The disorder was formerly thought to be an extreme case of caudal regression syndrome; however, it was reclassified to be considered a separate condition.
3. Proteus Syndrome
This is the disease in which bones, skin, and other tissues are overgrown. Individuals typically have organs and tissues that grow out of proportion with the rest of their body. Because the overgrowth varies and exhibits no apparent order, it can result in strange and imbalanced features. No signs of the disorder appear until about 6 to 18 months after birth.
The proteus syndrome can vary from individual to individual, and it is said to occur in less than one in one million people. And in fact, only a few hundred documented cases have ever been reported. This disorder results from a mutation in the AKT1 gene (which regulates cell growth), causing mosaicism, as cells grow and divide, some cells exhibit the mutation while others do not. The resulting mixture of normal and abnormal cells is what causes the overgrowth.
4. SCID
This disease is also known as Boy in the Bubble Disease. It’s a disorder in which individuals are born without any effective immune system. This disorder is caused by a number of genes, including those that cause defects in both T and B cell responses, which has a downstream negative effect on the production of lymphocytes (a type of white blood cell). SCID is also thought to arise due to the lack of adenosine deaminase (ADA). Interestingly, SCID was the first human illness treated by human gene therapy in 1990 and is increasingly being used to treat children
5. Ectrodactyly
Formerly known as “lobster claw hand, ”individuals with this disorder have a cleft where the middle finger or toe should be. These split body malfunctions are rare limb deformities that can manifest in any number of ways, including cases including only the thumb and one finger. It’s also associated with hearing loss. Genetically speaking, it’s caused by several factors, including deletions, translocations, and inversions in chromosome 7.
6. Lesch–Nyhan Syndrome
LNS is a genetic disorder that affects one in every 380,000 births, nearly all of the boys. This results in an overproduction of uric acid, a waste product of normal chemical processes that are found in blood and urine. The disease also affects neurological function and behavior. Individuals exhibit involuntary body movements, like tensing muscles, jerking movements, and flailing limbs. Self-mutilating behaviors are also common, including headbanging, and lip and finger biting. Individuals can be given allopurinol to help with gout, but treatments for the neurological and behavioral aspects of the disease remain out of reach.
7. Epidermodysplasia verruciformis
Epidermodysplasia verruciformis is a very rare disorder that makes people prone to widespread human papillomavirus (HPV) infection. This infection can cause scaly macules and papules to grow on the hands, feet, and even face. These skin “eruptions” appear as wart-like lesions and even wood-like and horn-like growths with reddish-brown pigmented plaques.
Typically, skin tumors start to emerge in people between the age of 20 and 40, and the growths tend to appear in areas exposed to the sun. Also called Lewandowsky-Lutz dysplasia, there is no known cure, though treatments to scale back the growths are possible.
8. Trimethylaminuria
Individuals with this condition cannot break down the naturally occurring but pungent-smelling trimethylamine, literally smell like rotting fish, rotting eggs, garbage, or urine. It’s for this reason that it’s also called the Fish Odor Syndrome. Trimethylaminuria is found in sweat, urine, exhaled breath, and other bodily secretions. But for individuals with this disorder, typically women, it shows up in abnormal amounts. The severity of the odors seems to peak just before and during menstrual periods and after taking oral contraceptives. Consequently, people with trimethylaminuria have an exceptionally difficult time in social settings. The odor can vary in intensity over time, but many people experience depression and social isolation as a result.
9. Hypertrichosis
Hypertrichosis is called “werewolf syndrome” that affects as few as one in a billion people, and in fact, only 50 cases have been documented since the Middle Ages. People with hypertrichosis have excessive hair on the shoulders, face, and ears. Studies have implicated it to a rearrangement of chromosome 8. It happens due to a disruption of the “crosstalk” between the epidermis and the dermis as hair follicles form in the 3-month fetus at the eyebrows and down to the toes. Most of our body parts ignore the messages to form follicles, which explains why most of us are relatively hairless.
10. Uner Tan Syndrome
Uner Tan syndrome is a condition in which people who suffer from it walk on all fours. UTS is a syndrome that was proposed by the Turkish evolutionary biologist Üner Tan after studying five members of the Ulaş family in rural Turkey. These individuals walk with quadrupedal locomotion, use primitive speech, and have a congenital brain impairment (including “disturbed conscious experience”).
The family was featured in a 2006 BBC2 documentary called, “The Family That Walks On All Fours.” The new syndrome says Tan, “may be used as a live model for human evolution.” Some experts think this is bunk, and that genetics may have very little to do with it.
Source: io9.gizmodo.com
