Nezelof syndrome is an autosomal recessive congenital immunodeficiency condition due to underdevelopment of the thymus. 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, 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
Pyoderma
Emphysema
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 bodys blood circulation Hassals 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 (B-cells will be normal)
X-ray of thymus (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 therapy
IV immunoglobulin
Bone marrow transplantation
Thymus transplantation
Thymus factors

See also
List of radiographic findings associated with cutaneous conditions

References
Further reading
Lavini, Corrado; Moran, Cesar A.; Uliano, Morandi; Schoenhuber, Rudolf (2009-05-08). Thymus Gland Pathology: Clinical, Diagnostic and Therapeutic Features. Springer Science & Business Media. ISBN 9788847008281. External links
PubMed
Stones may show up on XR with a fuzzy gray appearance. They are radioopaque due to sulfur content, though more difficult to visualize than calcium oxalate stones. Treatment
Initial treatment is with adequate hydration, alkalization of the urine with citrate supplementation or acetazolamide, and dietary modification to reduce salt and protein intake (especially methionine). If this fails then patients are usually started on chelation therapy with an agent such as penicillamine. Tiopronin is another agent. Once renal stones have formed, however, the first-line treatment is endoscopic laser lithotripsy. ESWL (Extracorporeal shock wave lithotripsy) is often not effective because of the hardness of the stones that do not fragment easily. Conventional open-abdominal surgery is rarely used but has proven to be effective treatment modalities for patients with more advanced disease. Adequate hydration is the foremost aim of treatment to prevent cystine stones. The goal is to increase the urine volume because the concentration of cystine in the urine is reduced which prevents cystine from precipitating from the urine and forming stones. People with cystine stones should consume 5 to 7 liters a day. The rationale behind alkalizing the urine is that cystine tends to stay in solution and causes no harm. In order to alkalize the urine, sodium bicarbonate has been used. One must be careful in alkalizing their urine because it could lead to other forms of stones in process of preventing cystine stones. Penicillamine is a drug that acts to form a complex with cystine that is 50 times more soluble than cystine itself.