Genetics

Leave a comment Posted on May 29, 2017May 29, 2017 A to Z of Medical Conditions, Genetics

Thalassaemia – get informed here

Thalassaemia

Thalassaemia is the name for a group of inherited conditions that affect a substance in the blood called haemoglobin.

People with the condition produce either no or too little haemoglobin, which is used by red blood cells to carry oxygen around the body. This can make them very anaemic (tired, short of breath and pale).

It mainly affects people of Mediterranean, South Asian, Southeast Asian and Middle Eastern origin.

There are a number of types of thalassaemia, which can be divided into alpha and beta thalassaemias. Beta thalassaemia major is the most severe type. Other types include beta thalassaemia intermedia, alpha thalassaemia major and haemoglobin H disease.

It’s also possible to be a “carrier” of thalassaemia, also known as having the thalassaemia trait. Thalassaemia carriers don’t have any serious health problems themselves, but are at risk of having children with the condition.

Symptoms of thalassaemia

Most people born with thalassaemia experience problems from a few months after birth. Less severe cases may not be noticeable until later in childhood or even until adulthood.

The main problems associated with thalassaemia are:

anaemia – severe tiredness (fatigue), weakness, shortness of breath, noticeably pounding, fluttering or irregular heartbeats (palpitations), and pale skin caused by the lack of haemoglobin
excess iron in the body – this is caused by the regular blood transfusions used to treat anaemia and it can cause problems with the heart, liver and hormone levels if untreated

Some people experience other problems such as delayed growth, weak and fragile bones (osteoporosis), and reduced fertility.

Read more about the symptoms of thalassaemia.

Causes of thalassaemia

Thalassaemia is caused by faulty genes that affect the production of haemoglobin.

A child can only be born with the condition if they inherit these faulty genes from both parents.

For example, if both parents have the faulty gene that causes beta thalassaemia major, there’s a 25% chance of each child they have being born with the condition.

The parents of a child with the condition are usually carriers of thalassaemia (see below). This means they only have one of the faulty genes that causes the condition.

Read more about the causes of thalassaemia.

Screening and testing for thalassaemia

Thalassaemia is often detected during pregnancy or soon after birth.

Screening for thalassaemia in pregnancy is offered to all pregnant women in England to check if there’s a risk of a child being born with the condition, and some types may be picked up during the newborn blood spot test (heel prick test).

Blood tests can also be carried out at any age to check for the condition or to see if you’re a carrier of a faulty gene that causes it.

Read more about screening and testing for thalassaemia.

Treatments for thalassaemia

People with thalassaemia major or other serious types will need specialist care throughout their lives.

The main treatments are:

Blood transfusions – regular blood transfusions are given to treat and prevent anaemia; in severe cases these are needed around once a month.
Chelation therapy – treatment with medications to remove the excess iron from the body that builds up as a result of having regular blood transfusions. Some people experience a build-up of iron even without transfusions and need treatment for this.

Eating a healthy diet, doing regular exercise and not smoking or drinking excessive amounts of alcohol can also help to ensure you stay as healthy as possible.

The only possible cure for thalassaemia is a stem cell or bone marrow transplant, but this isn’t done very often because of the significant risks involved.

Read more about how thalassaemia is treated and living with thalassaemia.

Outlook for thalassaemia

Although the main problems associated with thalassaemia can often be managed with treatment, it’s still a serious condition that can have a significant impact on a person’s life.

Even in mild cases with few symptoms, there’s still a risk you could pass on a more serious form of the condition to your children.

Without close monitoring and regular treatment, the most severe types can cause serious organ damage and can be life-threatening.

In the past, severe thalassaemia was often fatal by early adulthood. But with current treatments, average life expectancy is expected to increase significantly, with people likely to live into their 50s, 60s and beyond.

Carriers of thalassaemia (thalassaemia trait)

A carrier of thalassemia is someone who carries at least one of the faulty genes that causes thalassaemia, but doesn’t have the condition themselves. It’s also known as having the thalassaemia trait.

People with this trait won’t develop severe thalassaemia, but are at risk of having a child with the condition if their partner is also a carrier.

You can request a blood test to check if you’re a carrier of thalassaemia from your GP surgery or nearest sickle cell and thalassaemia centre.

Read more about being a thalassaemia carrier.

Leave a comment Posted on March 19, 2017March 19, 2017 Genetics

Turner syndrome – what are the signs and symptoms of Turner syndrome?

Turner syndrome

Turner syndrome is a genetic disorder that affects about 1 in every 2,000 baby girls and only affects females.

A girl with Turner syndrome only has one normal X sex chromosome, rather than the usual two (XX).

This chromosome variation happens randomly when the baby is conceived in the womb. It is not linked to the mother’s age.

Characteristics of Turner syndrome

Females with Turner syndrome often have a wide range of symptoms and some distinctive characteristics. Almost all girls with Turner syndrome:

are shorter than average

have underdeveloped ovaries (female reproductive organs), resulting in a lack of monthly periods and infertility

As height and sexual development are the two main characteristics, Turner syndrome may not be diagnosed until a girl fails to show sexual development associated with puberty, usually between the ages of 8 and 14 years.

Other characteristics of Turner syndrome can vary significantly between individuals.

Treating Turner syndrome

There is no cure for Turner syndrome, but many of the associated symptoms can be treated.

Girls and women with Turner syndrome will need to have regular health checks of their heart, kidneys and reproductive system throughout their lives. However, it is usually possible to lead a relatively normal and healthy life.

Life expectancy is slightly reduced, but it can be improved with regular health checks to identify and treat potential problems at an early stage.

Leave a comment Posted on March 18, 2017March 18, 2017 Genetics

Edwards’ syndrome – so what is Edwards’ syndrome and why do we need to know?

Edwards’ syndrome

Introduction

[Original article on NHS Choices website]

Edwards’ syndrome, also known as trisomy 18, is a serious genetic condition caused by an additional copy of chromosome 18 in some or all of the cells in the body.

Each cell normally contains 23 pairs of chromosomes, which carry the genes you inherit from your parents, but a baby with Edwards’ syndrome has three copies of chromosome number 18, instead of two.

This disrupts the baby’s normal development and, in many cases, causes them to be miscarried or stillborn.

Babies with Edwards’ syndrome will have grown slowly in the womb and will have a low birthweight, along with a number of other serious medical problems. Of those that survive to birth, around half will die within two weeks and only around one in every five will live at least three months.

Around one in every 12 babies born with Edwards’ syndrome survive beyond one year, and they will live with severe physical and mental disabilities. Some children do survive to early adulthood, but this is very rare.

Edwards’ syndrome affects around one in 3,000 to 6,000 live births.

What are the features and symptoms?

Babies with Edwards’ syndrome can have a wide range of different problems.

Physical signs of Edwards’ syndrome include:

a small, abnormally shaped head

a small jaw and mouth

long fingers that overlap, with underdeveloped thumbs and clenched fists

low-set ears

smooth “rocker bottom” feet (with a rounded base)

a cleft lip and palate (a gap or split in the upper lip and/or the roof of the mouth)

an exomphalos (where the intestines are held in a sac outside the tummy)

Babies with Edwards’ syndrome also typically have:

heart and kidney problems

feeding problems – leading to poor growth

breathing problems

hernias in the wall of their stomach (where internal tissues push through a weakness in the muscle wall)

bone abnormalities – such as a curved spine

frequent infections of the lungs and urinary system

a severe learning disability

How does Edwards’ syndrome happen?

Edwards’ syndrome is rarely inherited and the condition is not caused by anything the parents have done.

The development of three copies of chromosome 18 usually happens randomly during the formation of eggs and sperm. There is an error in the division of cells, and the extra chromosome is either in the egg cell produced by the mother or in the sperm cell produced by the father.

As this happens randomly, it’s extremely unlikely for parents to have more than one pregnancy affected by Edwards’ syndrome.

The chance of having a baby with Edwards’ syndrome increases with the mother’s age.

Types of Edwards’ syndrome

There are two main types of Edwards’ syndrome.

Full form

Approximately 94% of babies with Edwards’ syndrome will have the full form, where every cell in their body has three copies of chromosome 18, instead of two. Most babies with this form will die before infancy.

Mosaic trisomy 18

About 5% of babies with Edwards’ syndrome will have the extra copy of chromosome 18 in only some of their body cells. This less severe form of the disease is known as mosaic trisomy 18.

The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. Some babies may only be mildly affected, while some can be severely disabled.

Around seven in every 10 babies born with mosaic trisomy will live for at least a year and, in rare cases, babies with the condition may survive into early adulthood.

Testing for Edwards’ syndrome during pregnancy

Pregnant women are offered screening for Edwards’ syndrome between 10 and 14 weeks of pregnancy to assess the chances of their baby having the condition.

The screening test, known as the combined test, comprises a blood test plus a nuchal translucency ultrasound scan (nuchal translucency is a collection of fluid at the back of the baby’s neck). This test also screens for Down’s syndrome and Patau’s syndrome.

Later in pregnancy, usually when you are 18 to 21 weeks pregnant, you will also be offered a scan that looks for physical abnormalities and 11 rare conditions, including Edwards’ syndrome.

Is there any treatment?

There is no cure for Edwards’ syndrome and the symptoms can be very difficult to manage. You are likely to need help from a wide range of health professionals.

Treatment will focus on immediately life-threatening issues, such as infections and heart problems. Your child may also need to be fed through a feeding tube, if feeding is a problem.

If limb abnormalities affect your child’s movements as they get older, they may benefit from supportive treatment, such as physiotherapy and occupational therapy.

Depending on your child’s specific problems, they may need specialist care in hospital or a hospice, or you may be able to look after them at home with appropriate support.

Leave a comment Posted on March 13, 2017March 14, 2017 Genetics, Patient Talk

What testing your DNA can tell you

Do I need to test my DNA?

Good question.

A fair few medical conditions have a genetic component. Breast cancer and celiac disease for two example.

Them there are other condition like autism where the jury is still out but it does seem a strong possibility!

So it can be worth checking. This infographic gives you a bit more information on DNA testing should you chose to do so!

From Visually.

Leave a comment Posted on March 1, 2017March 1, 2017 Genetics

Prader-Willi syndrome -what are the signs and symptoms of Prader-Willi syndrome?

Prader-Willi syndrome

Introduction

[Original article on NHS Choices website]

Prader-Willi syndrome (PWS) is a rare genetic condition that causes a wide range of problems.

These may include:

a constant desire to eat food, which seems driven by a permanent feeling of hunger and can easily lead to dangerous weight gain

restricted growth, leading to short stature

reduced muscle tone (hypotonia)

learning difficulties

lack of sexual development

behavioural problems, such as temper tantrums or stubbornness

What causes Prader-Willi syndrome?

Prader-Willi syndrome is caused by a genetic defect on chromosome number 15, which happens purely by chance.

The condition is rare, affecting no more than one in every 15,000 children born in England. Boys and girls of all ethnic backgrounds may be affected.

Read more about the causes of Prader-Willi syndrome.

Diagnosing Prader-Willi syndrome

Prader-Willi syndrome can usually be confirmed by carrying out genetic tests.

A checklist of symptoms that are typical of Prader-Willi syndrome is often used to identify children who should be tested.

Read more about how Prader-Willi syndrome is diagnosed.

Living with Prader-Willi syndrome

There’s no cure for Prader-Willi syndrome, so treatment aims to manage the symptoms and associated problems. For parents, this includes dealing with their child’s excessive eating and behavioural problems.

Trying to get your child to stick to a healthy, balanced diet and maintain a normal weight is one of the most important parts of caring for a child with Prader-Willi syndrome. It’s also probably one of the most challenging and frustrating.

If children are allowed to eat as much as they want, they’ll quickly become dangerously overweight. A child with the syndrome can eat three to six times more than other children of the same age and still feel hungry.

However restricting a child’s diet is not easy. They can be highly obsessive when it comes to eating, and their hunger can cause them to hide or steal food.

Read more about managing Prader-Willi syndrome.

Outlook

While Prader-Willi syndrome itself isn’t life- threatening, the compulsive eating and resulting weight gain can be.

Young adults with the syndrome often develop obesity-related conditions usually seen in older adults, such as type 2 diabetes and heart failure. If the obesity isn’t treated, a person with the syndrome will probably die a lot younger than would normally be expected.

Compulsive eating can also cause health problems such as an abnormally expanded stomach and choking. Due to the potential risk of choking, all parents of a child with Prader-Willi syndrome are advised to learn the Heimlich manoeuvre.

Read more about what to do if someone is choking.

If a child with Prader-Willi syndrome is able to follow a restricted diet and control their weight, there’s no reason why they can’t enjoy a good quality of life and take part in activities such as voluntary or part-time work. However, because of their behavioural problems and learning difficulties, it’s unlikely they’ll be able to live fully independent lives.