• Mutations in the FBN-1 gene on chromosome 15q21.1 cause connective tissue disorder. Fibrillin-1 (FBN-1) is a structural component of extracellular matrix microfibrils that is lacking in this condition.

• One in 10,000 to 20,000 people has Marfan Syndrome. It's an autosomal dominant condition, which means that people who have it have a 50% chance of passing it on to their offspring.

• People suffering from the diseases are very tall and have a thin body frame. Their arms and legs are excessively long, making them appear out of proportion. Their joints are extremely brittle and easily dislocate. Their face is long and narrow. Their chest protrudes or stretch down. They also have crowded teeth and an abnormal spine curvature. They have vision problems as a result of a dislocated lens, as well as heart problems as a result of weak tissue in their heart valves. It raises the risk of asthma, pneumonia, and lung collapse.

• It is caused by mutations in gene 7q31.2 which results to a disruption of the normal production and function of the CF transmembrane conductance regulator (CFTR) protein. The CFTR protein is essential because it helps to maintain the balance of salt and water on the surfaces of the human body such as the lungs.

• Cystic Fibrosis is an autosomal recessive disease that occurs in 1 of every 2,500–3,500 live births in most Caucasian and European ancestry with a lesser incidence rate in other ethnic groups such as Africans and Asians.

• The disease causes the build-up of very thick, sticky mucus in organs such as the lungs and pancreas. Because of this, people who have Cystic Fibrosis find it difficult to breathe and often have frequent respiratory infections. Other clinical presentations include very salty sweat, loose or oily stools, slow growth in children, and the inability to gain weight despite having good appetite and appropriate intake of calories.

• DMD is an inherited X-liked disease in a recessive pattern that has a defect on Xp21 locus, a specific locus on the short arm of the X-chromosomes. This happens when the gene production of dystrophin which is associated with the inner side of the membrane of cardiac and skeletal muscles are affected. Manifest mostly in males while the females that have a defective gene present on one of their X chromosomes are carriers for this disorder.

• According to CDC, DMD is a rare muscle disorder but has an estimated prevalence of 1 in every 7,250 males aged 5 – 24 years worldwide. Other literature states that the birth prevalence is estimated to be 1 in every 3,500 live male births. The age of onset is usually between 3 and 5 years of age. Duchenne muscular dystrophies as a whole are estimated to affect 250,000 individuals in the United States.

• Its clinical features include the following: toe walking, an unusual waddling manner of walking (gait), difficulty climbing stairs or rising from a sitting position (Gower’s sign), abnormal enlargement of the calves due to scarring of muscles (pseudohypertrophy), Tachypnea or bradypnea, decreased chest expansion, lordosis, scoliosis, calf muscle hypertrophy, foot drop, tight heel cord, backward bending of the knee, and muscle atrophy in thighs and buttock. 
• Specifically,
  • Early childhood: develop weakness and wasting (atrophy) of the muscles closest to the trunk (proximal muscles) such as those of the upper legs and pelvic area and upper arms and shoulder area,  muscle weakness and atrophy spread to affect the lower legs, forearms, neck, and trunk
  • Children with DMD: toe walking, an unusual waddling manner of walking (gait), difficulty climbing stairs or rising from a sitting position (Gower’s sign), and repeated falling
  • Toddlers and young children may seem awkward and clumsy and may exhibit abnormal enlargement of the calves due to scarring of muscles (pseudohypertrophy). Additional abnormalities may develop such as progressive curvature of the spine (scoliosis or lordosis), wasting of thigh and pectoral muscles, and abnormal fixation of certain joints (contractures). 
  • Late teens: weakness and deterioration of the heart muscle (cardiomyopathy), weakness and deterioration of muscles in the rib cage, increased susceptibility to respiratory infections, difficulty coughing, and, respiratory failure.

• This condition is characterized by a missing or partially missing X chromosome of the females. There is no presence of Barr bodies. 

• This occurs in 1 in 2000 to 3000 liveborn female births. However, its epidemiology is still unknown.

• Its features include heart shaped face, webbed neck, small mandible, high-arched palate with overcrowding teeth, low set ears, low hairline, widely spaced nipples, and short fingers and toes.  Breasts, pubic hair and menstruation are usually absent. Atrophy of ovary progresses after birth.

• A genetic condition wherein a male has 2 or more X chromosomes (47, XXY, 48, XXXY, or 49, XXXXY).

• It occurs in 1 of every 500 or 1000 male births, making it one of the most common human sex chromosome disorders.

• They have small, soft testes that produce few sperm or are sterile due to seminiferous tubules atrophy. 
• There is low libido and impotence.
• Only sparse pubic, axillary, and chest hair can be found. 
• Most would have small IQ points ranging between 10 to 15. 
• A blood test would show high gonadotropin and low testosterone levels. 
• Other clinical presentation include scoliosis, varicose veins, leg ulcers, emphysema, diabetes mellitus, and thyroid problems.

• Fragile X syndrome (FXS) is a genetic disorder caused by a change to a gene on the X-chromosome called the FMR1 gene

• FXS affects approximately 1 in 2500-4000 males and 1 in 7000-8000 females

• FXS is characterized by moderate intellectual disability in affected males and mild intellectual disability in affected females. 
• Affected males may also present with large, protruding ears, long face, high-arched palate, hyperextensible finger joints, double-jointed thumbs, flat feet, soft skin, and postpubescent macroorchidism 

• Edward’s syndrome is also known as Trisomy 18, 47,XY, +18. It is a rare but serious condition. A baby with Edwards' syndrome has 3 copies of chromosome number 18 instead of 2. This affects the way the baby grows and develops. Most babies with Edwards' syndrome will die before or shortly after being born.

• 1/3,000 babes born alive with Edward’s syndrome will live past their 1^st birthday

• Clinical features usually depend on whether they have full, mosaic, or partial Edward’s syndrome. But commonly, the manifest Severe, clenched fist with survival less than 1 year. 

• Extra chromosome 18 is present in all cells. 
• The effects of full Edward's syndrome are often more severe. 
• Most babies with this form will die before they are born.
  
  

• Also known as Mosaic Trisomy 18
• Have an extra chromosome 18 in just some cells.
•  Lead to milder effects of the condition, depending on the number and type of cells that have the extra chromosome. Most babies with this type of Edward's syndrome who are born alive will live for at least a year, and they may live to adulthood.
  
  

•  A very small number of babies with Edwards' syndrome (about 1 in 100) have only a section of the extra chromosome 18 in their cells, rather than a whole extra chromosome 18.

• Down syndrome is an inherited disorder that is caused by trisomy 21 in which the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This condition is caused by abnormal cell division during the development of the sperm cell or the egg cell.

• According to WHO, the estimated incidence of Down syndrome is between 1 in 1,000 to 1 in 1,100 live births worldwide.

• People who inherited this condition possesses low muscle tone, small stature, and a single deep crease across the center of the palm.
• Facial appearance is flattened, outside corners of the eyes that point upward (upward slanting palpebral fissures ), small ears, a short neck , and a tongue that tends to stick out of the mouth.
• Mental impairment, abnormal teeth, stunted growth, umbilical hernia, congenital heart disease, abnormal pelvis, and big toes widely spaced.

• Hemophilia is an X-linked recessive hereditary disorder. It involves changes or mutations on the X chromosome, particularly on genes F8 and F9. These mutations will cause a deficiency in a patient's proteins known as the clotting factors.
• Depending on the type of hemophilia, the type of clotting factor affected will vary, for example, hemophilia A is caused by a deficiency in factor VIII, hemophilia B is caused by a deficiency in factor IX, and hemophilia C is caused by a deficiency in factor XI.

• According to the CDC, Hemophilia A affects 1 in 5000 male births and 400 babies are born with hemophilia each year.
• Hemophilia A is more prevalent than Hemophilia B since it affects 80-85% of the total hemophilia population.
• Incidence of hemophilia is higher in geographical areas wherein there is a practice of consanguineous marriages. This is due to the X-linked recessive nature of the disease.
• The estimated number of people living with hemophilia worldwide is 400,000

• Bleeding into the joints. This can cause swelling and pain or tightness in the joints; it often affects the knees, elbows, and ankles.
• Bleeding into the skin or muscle and soft tissue causes a build-up of blood in the area 
• Bleeding of the mouth and gums, and bleeding that is hard to stop after losing a tooth.
• Bleeding after circumcision
• Bleeding after having shots, such as vaccinations.
• Bleeding in the head of an infant after a difficult delivery.
• Blood in the urine or stool.
• Frequent and hard-to-stop nosebleeds.

• High levels of total cholesterol and LDL cholesterol.
• A strong family history of high levels of total and LDL cholesterol and/or early heart attack.
• Elevated and therapy-resistant levels of LDL in either or both parents.
• Xanthomas (waxy deposits of cholesterol in the skin or tendons).
• Xanthelasmas (cholesterol deposits in the eyelids).
• Corneal arcus (cholesterol deposit around the cornea of the eye).
• If angina (chest pain) is present, it may be a sign that heart disease is present.

Vascular Ehlers-Danlos Syndrome is a genetic disorder that affects the connective tissues and is caused by a mutation in the COL3A1 gene (or sometimes COL1A1) on your long arm of Chromosome 2, which is responsible for making Type III collagen. EDS is autosomal dominant. classical EDS is usually characterized with a hyperflexible joints and stretchy skin, but vEDS is a more serious and fatal type of EDS because it affects the walls of the blood vessels and the uterus.

• The incidence of true vEDS is actually quite rare, occuring at ranges between range between 1/50 000 and 1/200 000.
• This is due to the underdiagnoses of both the symptomatic and the milder form of the disease.
• The combined prevalence of all types of Ehlers-Danlos syndrome appears to be at least 1 in 5,000 individuals worldwide. 

Vascular EDS is often considered to be the most serious type of EDS

• Easy bruising on the skin
• Thin skin with visible small blood vessels, which are particularly on the upper chest and legs
• Fragile blood vessels that can bulge or tear. Hematoma is often seen as a result and may cause in serious internal bleeding
• Many risks of organ problems, such as the bowel tearing, the womb tearing (in late pregnancy) and partial collapse of the lung
• cEDS signs such as hypermobile fingers and toes, andunusual facial features which are categorical for vEDS (such as a thin nose and lips, large eyes and small earlobes), varicose veins
• Delayed wound healing

• There are two types of Alzheimer's-the early and late-onset. Researchers have not found a specific gene that can causes late-onset Alzheimer's disease, but having a genetic variation of the apolipoprotein E (APOE) gene on chromosome 19 does increase a person's risk. The APOE gene is involved in making a protein that helps carry cholesterol and other types of fat in the bloodstream. for the early-onset having any of these single-gene mutations may associate with the early type, namely: Amyloid precursor protein (APP) on chromosome 21, Presenilin 1 (PSEN1) on chromosome 14, and Presenilin 2 (PSEN2) on chromosome 1.

• The incidence of having Alzheimer's Disease is at 70% for the aged group of seniority specifically at age 75 above. In addition, about 1-9% in the age group of 65 and older.

• Showing a wide range of memory loss
• Confusion
• Inability to know and learn things
• Difficulty with language in terms of reading, writing, or even thinking
• Difficulty in analyzing logical things
• Shortened attention span
• Problem coping with new situations

• Type 1- does not affect the nervous system and appear early in life; mild
• Type 2- affect the nervous system; causes serious medical problems in infants
• Type 3- affect the nervous system; progress slowly than type 2 

• 1 in 50,000- 1 in 100,000 in general population
• type 1 is more frequent in Ashkenazi Jewish decent
• type 1 present in 1 to 500- 1 in 1,000
• 1 in 14 Ashkenazi Jewish is a carrier
• type 2 and 3 are not as common

• enlargement of liver and spleen
• anemia 
• easy bruising (thrombocytopenia)
• bone disease (pain and fractures

• eye problems
• seizures
• brain damage
• skin problems
• excessive fluid accumulation

• Wolf-Hirschhorn syndrome (WHS) or also called as 4p- syndrome/ Pitt-Rogers-Danks syndrome/ monosomy 4p. It is a very rare chromosomal condition caused by a missing segment of the short arm of chromosome 4 (partial deletion or monosomy).

• Since it’s a very rare disorder, several studies for over 25 years suggested that WHS occurred in only 1/50,000 of the population with a female to male ration of 2:1.

• Broadening and prominence of the region between the brows at the top of their nose (the glabella). Characterized by big, wide-spaced eyes, arched eyebrows, and a diminutive lower face, which includes a short upper lip and a tiny mouth and jaw. Lack of indentation of the nasal bridge 
• Other typical findings include: microcephaly; eye variances (turning in or out of the eyes, drooping eyelids, eye deformities); cleft lip and/or palate; abnormalities of the penis, testicles, or vagina; abnormalities of the kidneys; issues with bones; problems with teeth.

• A musty odor in the breath, skin or urine, caused by too much phenylalanine in the body
• Neurological problems that may include seizures
• Skin rashes (eczema)
• Fair skin and blue eyes, because phenylalanine can't transform into melanin — the pigment responsible for hair and skin tone
• Abnormally small head (microcephaly)
• Hyperactivity
• Intellectual disability
• Delayed development
• Behavioral, emotional and social problems
• Psychiatric disorders

• "Cherry-red" spots in the eyes
• Loss of motor skills, including turning over, crawling and sitting up
• Muscle weakness, progressing to paralysis
• Seizures
• Vision loss and blindness
• Hearing loss and deafness
• Loss of mental functions and a lack of response to surroundings
• Growth in head size (progressive macrocephaly)

• Behavior problems
• Slow loss of vision and speech
• Frequent respiratory infections
• Seizures

• Muscle weakness
• Clumsiness and loss of coordination
• Tremors and muscle spasms
• Loss of the ability to walk
• Problems speaking and swallowing
• Psychiatric disorders
• Sometimes loss of mental function

• Type 1 Usher syndrome: MY07A, USH1C, CDH23, PCHD15, USH1G
• Type 2 Usher syndrome: USH2A, GPR98, DFNB31
• Type 3 Usher syndrome: CLRN1

• Profound hearing loss (only able to hear very loud sounds) or deafness at birth
• Loss of night vision by age 10, with severe vision loss by midlife
• Balance problems, including trouble sitting up and walking

• Moderate to severe hearing loss in early childhood
• Loss of night vision by teenage years, with severe vision loss by midlife
• Normal balance

• Normal hearing at birth, with hearing loss starting in childhood
• Loss of night vision by teenage years, with severe vision loss by midlife
• Normal balance

• SCD affects about 100,000 people in the United States.
• SCD affects roughly 1 in every 365 Black or African-American babies born.
• SCD affects roughly 1 in every 16,300 Hispanic-American babies born.
• Sickle cell trait affects about 1 in every 13 Black or African-American newborns (SCT).

• Anemia
• Episode of Pain
• Swelling of Hands and feet
• Infections
• Late growth and Puberty
• Vision problem

• Symptoms appear at birth or within an infant’s first six months of life.
• difficulty swallowing and sucking.
• They don’t meet typical milestones like holding up their heads or sitting.
• Most children with type 1 SMA die before their second birthday.

• appear when a child is between six months and 18 months old
• affect the lower limbs
• may be able to sit up but can’t walk
• Most children with type 2 SMA live into adulthood.

• appear after a child’s first 18 months of life
• Some people with type 3 don’t have signs of disease until early adulthood.
• mild muscle weakness, difficulty walking and frequent respiratory infections
• Over time, symptoms can affect the ability to walk or stand.
• doesn’t significantly shorten life expectancy

• rare adult form of SMA doesn’t typically appear until the mid-30s
• Muscle weakness symptoms progress slowly
• most people with type 4 remain mobile and live full lives