Nezelof syndrome is an autosomal recessive

congenital A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

immunodeficiency Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

condition due to underdevelopment of the thymus. The defect is a type of

purine nucleoside phosphorylase deficiency Purine nucleoside phosphorylase deficiency is a rare autosomal recessive metabolic disorder which results in immunodeficiency. Signs and symptoms In addition to the symptoms associated with immunodeficiency, such as depletion of T-cells, decline ...

with inactive phosphorylase, this results in an accumulation of deoxy-GTP which inhibits

ribonucleotide reductase Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase (rNDP), is an enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides. It catalyzes this formation by removing the 2'-hydroxyl group of th ...

. Ribonucleotide reductase catalyzes the formation of deoxyribonucleotides from ribonucleotides, thus, DNA replication is inhibited.

Symptoms and signs

This condition causes severe infections. it is characterized by elevated immunoglobulins that function poorly. Other symptoms are: *

Bronchiectasis Bronchiectasis is a disease in which there is permanent enlargement of parts of the bronchi, airways of the lung. Symptoms typically include a chronic cough with sputum, mucus production. Other symptoms include shortness of breath, hemoptysis, co ...

* Hepatosplenomegaly * Pyoderma *

Emphysema Emphysema, or pulmonary emphysema, is a lower respiratory tract disease, characterised by air-filled spaces ( pneumatoses) in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the alve ...

* Diarrhea

Cause

Genetically speaking, Nezelof syndrome is autosomal recessive. the condition is thought to be a variation of severe combined immunodeficiency (SCID). However, the precise cause of Nezelof syndrome remains uncertain

Mechanism

In the mechanism of this condition, one first finds that the normal function of the thymus has it being important in T-cell development and release into the body's blood circulation Hassal's corpuscles absence in thymus(atrophy) has an effect on T-cells.

Diagnosis

The diagnosis of Nezelof syndrome will indicate a deficiency of T-cells, additionally in ascertaining the condition the following is done: ::::::::::*

Blood test A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a cholester ...

(

B-cell B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted o ...

s will be normal) ::::::::::*X-ray of thymus (atrophy present)

Differential diagnosis

The differential diagnosis for this condition consists of

acquired immune deficiency syndrome Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ma ...

and

severe combined immunodeficiency syndrome Severe combined immunodeficiency (SCID), also known as Swiss-type agammaglobulinemia, is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations that result in diffe ...

Treatment

In terms of treatment for individuals with Nezelof syndrome, which was first characterized in 1964, includes the following(how effective bone marrow transplant is uncertain) : * Antimicrobial therapy * IV

immunoglobulin An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

* Bone marrow transplantation * Thymus transplantation * Thymus factors

References

External links

PubMed
{{Medicine Immunodeficiency Noninfectious immunodeficiency-related cutaneous conditions Autosomal recessive disorders