Nezelof syndrome is an

autosomal An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosom ...

recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

congenital immunodeficiency condition due to underdevelopment of the

thymus The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. ...

. The defect is a type of purine nucleoside phosphorylase deficiency with inactive phosphorylase, this results in an accumulation of deoxy-GTP which inhibits ribonucleotide reductase. Ribonucleotide reductase catalyzes the formation of deoxyribonucleotides from

ribonucleotides In biochemistry, a ribonucleotide is a nucleotide containing ribose as its pentose component. It is considered a molecular precursor of nucleic acids. Nucleotides are the basic building blocks of DNA and RNA. Ribonucleotides themselves are basic ...

, 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 *

Hepatosplenomegaly Hepatosplenomegaly (commonly abbreviated HSM) is the simultaneous enlargement of both the liver (hepatomegaly) and the spleen (splenomegaly). Hepatosplenomegaly can occur as the result of acute viral hepatitis, infectious mononucleosis, and his ...

Pyoderma Pyoderma means any skin disease that is pyogenic (has pus). These include superficial bacterial infections such as impetigo, impetigo contagiosa, ecthyma, folliculitis, Bockhart's impetigo, furuncle, carbuncle, tropical ulcer, etc.Page 348 in: Au ...

* Emphysema *

Diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

Cause

Genetically speaking, Nezelof syndrome is autosomal recessive. the condition is thought to be a variation of

severe combined immunodeficiency 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 ...

(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

has it being important in T-cell development and release into the body's

blood circulation The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

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 A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell r ...

, additionally in ascertaining the condition the following is done: ::::::::::* Blood test ( B-cells will be normal) ::::::::::*X-ray of

(atrophy present)

Differential diagnosis

The differential diagnosis for this condition consists of acquired immune deficiency syndrome and severe combined immunodeficiency syndrome

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 An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...

therapy * IV immunoglobulin *

Bone marrow transplantation Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce ...

* Thymus transplantation *

Thymus The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. ...

factors

References

External links

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