Inherited disorder or deficiency eg Thalassaemia/G6PD

[Angelmum]

Thalassaemia

It is an inherited condition, in which there is a disorder in the production of haemoglobin and which leads to anaemia (low red blood cell count). People with the disease have an inability to manufacture sufficient quantities of globin chains.

Treatment today, in 2001, is more advanced then what it was 10 years ago. A Thalassaemia patient can enjoy a good quality, normal life. Thalassaemia can be divided into major and minor. The person with the minor form can lead a normal life. He may not even realise he has the condition.

However, the major form is very serious. The person has severe anaemia requiring regular blood transfusions, and is liable to get a) infections from the blood transfusion, for example, Hepatitis, AIDS etc and B) Iron overload, which in turn causes heart complications and diabetes. The person with Thalassaemia major usually has a shortened life span.

Signs and symptoms
The symptoms of Thalassaemia depend on the genetic defect and its severity. The more severe the genetic defect, the less haemoglobin that is produced and the more severe the anaemia that results. Thalassaemia minor may not cause any symptoms. If it does, the most common symptom is long-term, mild anaemia.

Strictly speaking however, there may sometimes be no symptoms - as the definition of a symptom is something that is complained of by the patient. Thalassaemia minors do not realise they have Thalassaemia minor, so they do not complain. They are thus, "asymptomatic" or with no symptoms.

Children with Thalassaemia major are normal at birth but become anaemic between the ages of three months and eighteen months. They become pale; unable to eat and sleep well, and may vomit their feeds. If not treated, they usually die between one and eight years old.

Treatment / Prevention
Thalassaemia is an inherited disorder. When one parent carries the gene, there is a 50% chance of having a child with Thalassaemia minor with every pregnancy. None will get Thalassaemia major. When both parents carry the gene, there is a 25% chance of having a child with Thalassaemia major and a 50% chance of having a child with Thalassaemia minor with every pregnancy.

The chances are the same with each pregnancy, no matter how many children the couple may have.

Since Thalassaemia can be passed on from one generation to another, couples should go for screening if they are planning to get married or start a family. If you are already pregnant, and both you and your husband have Thalassaemia minor, you should go for a prenatal diagnostic test to find out whether your unborn baby has Thalassaemia major. Prenatal diagnosis can be done by chorionic villus sampling or foetal blood sampling. Both tests are conducted under ultrasound guidance.

Chorionic villus sampling involves obtaining some cells from the placenta for testing. This is done before 10 weeks of pregnancy.

Foetal blood sampling involves obtaining a small amount of foetal blood from the umbilical cord for testing. This procedure is done at about 18-20 weeks of pregnancy.

 

[Angelmum]

G6PD deficiency

G6PD deficiency is an inherited condition in which the body doesn't have enough of the enzyme glucose-6-phosphate dehydrogenase, or G6PD, which helps red blood cells (RBCs) function normally. This deficiency can cause hemolytic anemia, usually after exposure to certain medications, foods, or even infections. This condition is permanent.

Most people with G6PD deficiency don't have any symptoms, while others develop symptoms of anemia only after RBCs have been destroyed, a condition called hemolysis. In these cases, the symptoms disappear once the cause, or trigger, is removed. In rare cases, G6PD deficiency leads to chronic anemia.

With the right precautions, a child with G6PD deficiency can lead a healthy and active life.


About G6PD Deficiency
G6PD is one of many enzymes that help the body process carbohydrates and turn them into energy. G6PD also protects red blood cells from potentially harmful byproducts that can accumulate when a person takes certain medications or when the body is fighting an infection.

In people with G6PD deficiency, either the RBCs do not make enough G6PD or what is produced cannot properly function. Without enough G6PD to protect them, RBCs can be damaged or destroyed. Hemolytic anemia occurs when the bone marrow (the soft, spongy part of the bone that produces new blood cells) cannot compensate for this destruction by increasing its production of RBCs.


Causes of G6PD Deficiency
G6PD deficiency is passed along in genes from one or both parents to a child. The gene responsible for this deficiency is on the X chromosome.

G6PD deficiency is most common in African-American males. Many African-American females are carriers of G6PD deficiency, meaning they can pass the gene for the deficiency to their children but do not have symptoms; only a few are actually affected by G6PD deficiency.


G6PD Deficiency Symptom Triggers
Kids with G6PD deficiency typically do not show any symptoms of the disorder until their red blood cells are exposed to certain triggers, which can be:

illness, such as bacterial and viral infections
certain painkillers and fever-reducing drugs
certain antibiotics (especially those that have "sulf" in their names)
certain antimalarial drugs (especially those that have "quine" in their names)

Some kids with G6PD deficiency can tolerate the medications in small amounts; others cannot take them at all. Check with your doctor for more specific instructions, as well as a complete list of medications that could pose a problem for a child with G6PD deficiency.

Other substances can be harmful to kids with this condition when consumed — or even touched — such as fava beans and naphthalene (a chemical found in mothballs and moth crystals). Mothballs can be particularly harmful if a child accidentally swallows one, so ANY contact should be avoided.

禁用: 蚕豆（胡豆）, 珍珠粉, 奈（不接触 臭丸)
慎用：各种退热止痛药(何济公、小儿退热散）、薄荷（感冒灵颗粒、感冒清热颗粒、保济丸）、樟脑、川莲

Breastfeeding mother should not take any of the above too as the chemicals can reach the baby through breast milk.

Malaria - Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase).

Apart from these precautions, your child can live a normal life.


Symptoms of G6PD Deficiency
A child with G6PD deficiency who is exposed to a medication or infection that triggers the destruction of RBCs may have no symptoms at all. In more serious cases, a child may exhibit symptoms of anemia (also known as a hemolytic crisis), including:

paleness (in darker-skinned children paleness is sometimes best seen in the mouth, especially on the lips or tongue)
extreme tiredness
rapid heartbeat
rapid breathing or shortness of breath
jaundice, or yellowing of the skin and eyes, particularly in newborns
an enlarged spleen
dark, tea-colored urine
Once the trigger is removed or resolved, the symptoms of G6PD deficiency usually disappear fairly quickly, typically within a few weeks.

If symptoms are mild, no medical treatment is usually needed. As the body naturally makes new red blood cells, the anemia will improve. If symptoms are more severe, a child may need to be hospitalized for supportive medical care.


Caring for Your Child
The best way to care for a child with G6PD deficiency is to limit exposure to the triggers of its symptoms. With the proper precautions, G6PD deficiency should not keep your child from living a healthy, active life.


Complications
Rarely, kidney failure or death may occur following a severe hemolytic event.


What if my child is G6PD deficient?
Your baby may have to stay in the hospital a little longer for monitoring of Jaundice level.


G6PD carrier
Women have two X chromosomes. The gene for G6PD deficiency is on only one of your two X chromosomes so you should experience no serious consequences from being a G6PD-deficiency carrier. The same applies to your baby if it is a girl. She should experience no serious consequences from being a G6PD-deficiency carrier.

However, if your baby is a boy, he has a 50% chance of inheriting your X chromosome that bears the G6PD gene (that being his only X) so he will be G6PD deficient. Under certain circumstances, this can cause problems (mainly jaundice in the newborn period and anemia). These can be dealt with effectively as long as both your obstetrician and the pediatrician who will care for your child know in advance about your being a G6PD carrier. You should discuss this matter pronto with your ob and then with your pediatrician. (If you don't have a pediatrician, maybe your ob can recommend one).

 

[Angelmum]

Some names of disorder

Angelman Syndrome
Apert Syndrome
Arthrogryposis Multiplex Congenita
Asperger Syndrome
Attention Deficit Hyperactivity Disorder
Autism
Cerebral Palsy
CHARGE Syndrome
Cornelia de Lange Syndrome
Cri Du Chat Syndrome
Dandy-Walker Syndrome
De Morsier’s Syndrome
DiGeorge/Velocardiofacial Syndrome
Down Syndrome
Fetal Alcohol Syndrome
Fragile X Syndrome
Hydrocephalus
Kabuki Syndrome
Klinefelter Syndrome
Landau-Kleffner Syndrome Laurence-Moon-Bardet-Biedl Syndrome
Lennox-Gastaut Syndrome
Lesch-Nyhan Syndrome
Lissencephaly
Mitochondrial Myopathy
Muscular Dystrophy
Noonan Syndrome
Prader-Willi Syndrome
Rett Syndrome
Rubinstein-Taybi Syndrome
Sanfilippo Syndrome
Septo-Optic Dysplasia
Smith-Lemli-Opitz Syndrome
Smith-Magenis Syndrome
Spina Bifida
Spinal Muscular Atrophy
Sturge-Weber Syndrome
Trisomy 18/Edwards’ Syndrome
Tuberous Sclerosis
Williams Syndrome

More details: Rare disorder