Rh deficiency syndrome

Rh deficiency syndrome

Autosomal recessive inheritance, a 25% chance

Rh deficiency syndrome is a type of hemolytic anemia that involves erythrocytes whom membranes are deficient in Rh antigens. It is considered a rare condition.

The Rh deficiency syndrome, also known as Rh-null syndrome, is a blood disorder where people have red blood cells (RBCs) lacking all Rh antigens. The Rh antigens maintain the integrity of the RBC membrane and therefore, RBCs which lack Rh antigens have an abnormal shape.

Types and causes

There are two types of Rh deficiency syndrome:

• The regulator type is associated with many different changes (mutations) in the RHAG gene .
• The amorph type is caused by inactive copies of a gene (silent alleles) at the RH locus.

As a result, the RBCs do not express any of the Rh antigens. The absence of the Rh complex alters the RBC shape, increases its tendency to break down (osmotic fragility), and shortens its lifespan, resulting in a hemolytic anemia that is usually mild. These patients are at risk of having adverse transfusion reactions because they may produce antibodies against several of the Rh antigens and can only receive blood from people who have the same condition.

Symptoms and signs

• Anisocytosis - Occasional
• Hemolytic anemia - Very frequent
• Hepatosplenomegaly - Occasional
• Hypochromia - Frequent
• Hypoxemia - Occasional
• Increased red cell osmotic fragility - Very frequent
• Intrauterine growth retardation - Occasional
• Jaundice - Occasional
• Macrocytic anemia - Very rare
• Oligohydramnios - Occasional
• Reticulocytosis - Very frequent
• Spherocytosis - Frequent
• Spontaneous abortion - Occasional
• Stomatocytosis - Frequent
• Tachycardia - Occasional
• Tachypnea - Occasional

Diagnosis

In order to diagnose, your doctor or other health care provider will take a medical history by asking questions and may do some of the following tests

• Medical history
• Physical examination
• Genetic testing
• Clinical procedures
• Laboratory tests
• Imaging studies

Inheritance

Rh deficiency syndrome is inherited in an autosomal recessive manner.

Management

Management is individualized according to the severity of hemolytic anemia.

See also

• List of hematologic conditions
• RHAG