The most strange anomalies in medicine, all of them are rare diseases with bizarre signs and symptoms. Some of them have already been described in MedTempus. I indicate so with links. They are ordered from greater to smaller frequency.
10-Congenital insensitivity to pain
Frequency: 100 documented cases in U.S.A. The frequency in other countries is unknown and it is usually undiagnosed.
Cause: Recently discovered. It is caused by a mutation in a gene implicated in the synthesis of a type of sodium channel which is mainly located in neurons associated with the reception and transmission of pain stimulus.
Description: They are totally normal people in the sense of touch and in the sensibility of cool, heat, pressure and tickling. However, with a normal act wich would cause pain (as to nail a needle) it does not cause them any painful sensation. As a result of this, they usually die younger by traumatism and several injuries because of their lack of pain perception. They must be under supervision in early ages so that they can´t injure themselves.
9-Moebius Syndrome
Frequency: Around 80 documented cases in Spain, 200 in U.K… In Europe, around 300 kids appear with this syndrome each year.
Cause: Unknown. Nobody knows if those that are affected in the origine of the disesase are nerves, brain stem or muscles. Many and varied hypothesis but without proofs that confirm them.
Description:Because some face nerves are not developed, the people who are born with this syndrome lack face expression. They cannot smile, frown, move the eyes laterally or control the blinking. They are often found sleeping with the open eyes. They have great difficulties in sucking, swallowing, speaking and any activity in which are implied muscles of the face.
8-True Hermaphroditism
Frequency: Around 500 documented cases in the world. The real frequency in the population is not known.
Cause: Hermaphrodites are chimeras. It is caused by the fusion of two zygotes of differente sex. That is to say, a first spermatozoid would fertilize a ovum and, later, another spermatozoid would fertilize another ovum. The zygotes that would be formed and that were destined to being twins, end up fusing and becoming an only individual that, genetically, is woman and man at the same time. It is unknown why that fusion of zygotes takes place.
Description: Hermaphrodites have both testicular and ovarian tissue. These two can be mixed, wich is called ovotestis or be separated elements, on the one hand a testicle and on the other an ovary. The external genitals are ambiguous and have components of both sexes. Hermaphrodites can have femenine or masculine appearance.
7-Fibrodysplasia ossificans progressiva
Frequency: 200-300 documented cases around the world. This anomaly is often undiagnosed. It is estimated that one case appears in two million births.
Cause: Unknown. It is a disease with autosomal dominant inheritance. Several genes in charge to synthesize bone growth factors are implied.
Description:
Any small injury to connective tissue (muscles, ligaments, and tendons) can result in the formation of hard bone around the damaged site. Children are born with a characteristic malformation of the great toes and begin to develop heterotopic (extra) bone formation during early childhood. Eventually, a second skeleton begins to form that severely restricts mobility.
In many cases, injuries can cause joints to become permanently frozen in place. The growths cannot be removed with surgery because such removal causes the body to «repair» the area of surgery with more bone.
6-Ondine’s curse (Congenital Central Hypoventilation Syndrome)
Frequency: Between 200-300 well-known cases all around the world. For being cause of sudden death it is thought that the well-known cases are only the tip of iceberg and that, in fact, 1 baby of each 200,000 which they are born could have this disease.
Cause: Partially known. The main cause is one or several mutations of PHOX2B gene with Autosomal Dominant Inheritance. The mechanisms of the involuntary breathing do not work properly. When sleeping, the chemical receptores that receive signals (low oxygen or the increase of carbon dioxide in blood) do not get to transmite the necessary nervous signals so that the breathing occurs.
Description: In slightest forms of Ondine’s Curse, the patient will be able to continue living but, because of unrestful sleep by the lack of oxygen, during the day he will be sleepy, gotten tired easily. He will have headaches, increase of the red cell levels…
The most serious forms, in which to sleep means a certain death, usually appear from the birth, and most of newborns die without knowing the cause. Nevertheless, in those people in which the disease has gotten worse progressively and get to risk life whenever they sleep, it is usually treated with assisted ventilation during the night.
Even so, in spite of all those treatments, any mistake to remain slept without the indicated oxygen therapy, will mean the death.
5-Proteus Syndrome 
Frequency: At the moment, 200 documented cases all around the world. It seems that a case apperars by more of a million births.
Cause: Unknown. Authors defend that it is probably caused by a somatic mosaicism of a lethal dominant gene. Other authors suggest that it is caused by a recombination in the embryo, giving rise to three types of cells: Normal cells, cells of minimum growth and cells of excessive growth.
Description: Exists a great amount of cutaneous and subcutaneous malformations, with hyperpigmentation, vascular malformations and irregular growth of bones. Partial gigantism of the limbs and the excessive growth of the fingers whereas some zones of the body grow less that what they would have. All of this causes an extreme disfigurement of the person who oftehn are socially. Josep Merrick, the famous “Elephant Man”, suffered from this syndrome.
4-Progeria (Hutchinson-Gilford Syndrome)
Frequency: Around 100 documented cases. It seems that appears a case of progeria by each 8 million births, although could be greater since it isn’t diagnosed many times.
Cause: Partially Known. Most of the cases of progeria take place by mutations of autosomal dominant inheritance in LMNA gene. This gene participates in the maintenance of nuclear stability and the organization of chromatin. It could also take part in the regulation of genetic expression, synthesis and repair of DNA
Description: People with progeria age very quickly from the childhood. When they are newborns they have a totally normal appearance but they are growing more and more slowly that the other children and develop a very characteristic face expression. The lose their hair, acquire wrinkles and suffer a severe damage on the arteries (atherosclerosis) that cause the death in the first years of adolescence.
3- True Human Tail (Vestigial Tail)
Frequency: Around 100 documented cases all around the world.
Cause: It isn´t well known. Some scientists think it is caused by a mutation of the genes that produce the cellular death that were detined to create a tail.
Description: It is observed the presence of a vestigial tail in the final zone of the sacral bone. This tail is compound of conective tissue, muscles, blood vessels, nerves, skin, vertebrae and cartilage.
2-Parasite Twin (Fetus in Fetus)
Frequency: Around 100 documented cases around the world.
Cause: It is a exaggerated case of siamese twins. Two twins don´t get to separate completely when they are zygotes and they are united by some zone. One of these twins grows healthy whereas the other degenerates, remaining inside the healthy twin and depending completely on him. It is unkown why these twins don´t separate correctly.
Description: When the host fetus is able to survive the childbirth, this one can show a swelling up in the zone where the parasitic fetus locates itself. 80% of
times, they are in the abdominal region, but also in skull, sacral region, scrotum… It can grow unnoticed, at the beginning. Later, the parasitic fetus will continue to grow at the same time the host does.
When making imaga tests, the organs are observed in places where the wouldn´t have to exist. Although tiny legs, arms, fingers, hair or any other element of the fetus can be seen if he has developed them. There aren´t two equal cases of fetus in fetus, since parasitic fetus can locate themselves in very different zones in host fetus and, therefore, the growth and elements that has gotten to develop will be variable. There are very developed parasitic fetuses and others that only have a little number of organs.
1-Human Werewolf Syndrome (Congenital Hypertrichosis Lanuginosa)
Frequency: 40-50 documented cases around the world from its discovery. The natural incidence (without counting the cases in families) is considered in a case between 1 billion or one by 10 billion inhabitants. 
Cause: Unknown. Some scientists state that it is caused by a mutation with autosomal dominant inheritance. The majority is caused by familiar inheritance and, very rarely, the mutation occurs spontaneously.
Description: People who suffer from it are completely covered in
Lanugo is the thin and off-white hair that appears in newborn in their shoulders and arms and that normally disappears after the first month from the birth. In those who suffer from this syndrome lanugo persists and can grow forever or dissapear over the years.lanugo hair except in the palms of their feet and hands. The maximum hair lenght that has been documented is about 25 centimeters.
Interesantissímo, además en inglés ayuda a refrescarme la memoria xD. Para mí el mas raro es el de Proteus, que me parece bastante raro y bastante traumatico para el que lo tiene… aunque todos son traumaticos…
Congenital insensitivity to pain
I watched a movie in my childhood cant remember details. Movie was about a covered organization formed by people who cant feel pain. They are the bad guys ‘though.
Anyway, take care…
You mean Time Runner? Starring Mark Hamill. It was early 90s cheese at it’s best.
Muy interesante y, pese a estar en inglés y resultar un texto técnico, se entiende todo perfectamente.
Como curiosisdad, de la enfermedad número 1, Human Werewolf Syndrome, hace muy poco que vimos en España un capítulo del CSI las Vegas, donde uno de sus protagonistas la padecía. En ese episodio, la chica en cuestión no había salido nunca de casa y por tanto estaba sin diagnosticar. Cuántos casos de ese tipo con enfermedades extrañas nacerán y morirán en las profundidades de los países sin que nadie nunca llegue a registrarlos?
También hemos visto otra variante de estas enfermedades recientemente en la TV, en concreto la 10, la del dolor, en un episodio de House donde a diferencia de lo descrito arriba, la paciente no sentía nada de nada en su cuerpo, ni frío ni calor. Mucho menos una enorme tenia de 7 metros que tenía de paso en sus intestinos matándola y que House le extrajo sin anestesia.
Ya sabemos dónde miran los guionistas para documentarse ;P.
Etnas:
Es una traducción (aunque tengo que mejorar todavía mucho mi inglés) de un post que escribí hace tiempo:
Las 10 Anomalías más raras en Medicina
«Cuántos casos de ese tipo con enfermedades extrañas nacerán y morirán en las profundidades de los países sin que nadie nunca llegue a registrarlos?»
Teniendo en cuenta la marginación social que suelen acarrear… me da que más de lo que imaginamos.
Freaky! Maybe move the description in front of the frequency and cause, makes it easier to read.
Have met 3 of #2-Twin-in-twin, in Florida, all in the abdomin. One woman, found out at age 19, had to have multiple surgeries, one ovary removed, feared never to give birth, she is mother now, to a very beautiful, normal, girl.
From a family of exceptional beauty, She and her brother had been photographic models, until she started suffering illness upon eating any meal, at age 19.
Doctors found her fetal twin in her abdomin, and now weighing about 16 pounds, resembling a tumor, without form, but the tissue is fetal.
The tragedy of having to quit college (Dentistry), due to the pain, the medications, the surgeries, the side effects, are now over, and, 8 years later, she is a very happy woman.
I like to think that the many prayers of all who met her and discovered the case have helped, and I thank God for the miracles, for the doctors actually predicted she would be barren of child.
She was very shy, and would not readily divulge her problems, until I had known her a year, as she was fiance, then wife, to a good friend.
The man and other woman also related to me they have had surgery, and are parents. I wondered as I had learned of these, plus, had heard of others, whether there is an epidemic, possibly based upon toxins in the environment.
Or, could it just be that in this huge tourist attraction of Central Florida, all roads bring the people here, and I am always curious, to learn things, and met many people, as Psychic reader in the Universal Studios, Islands of Adventure, Mystics of the Seven Veils, and as a used car consumer advocate, service manager, and dealer.
I wonder if some of these conditions could be behind the legends, such as Bigfoot, Yeti, werewolves, etc.
Does anyone know what the name of the birth defect (or deficiency) is that causes humans to have fin-like hands and/or feet? Also, what causes it? I saw someone over the weekend (and his child) that had that, and it kind of freaked me out, because I had never seen that before.
Thank you.
The condition you’re describing is probably ectrodactyly, which, literally translating to «monster hands,» is little better than the former title of lobster-claw syndrome. Children have a 50-50 chance of inheriting the congenital condition from their parents, so it does tend to be passed on through generations.
It’s caused by a mutation on certain chromosomes, and hopefully learning more about the condition will cause you to be less «freaked out» by people who look different in the future.