Autoimmune polyendocrinopathy associated with ring chromosome 18

A case report of Ring chromosome 18 with systemic Lupus Erythematosus and Crohn's disease

BACKGROUND

Ring Chromosome 18 is a rare chromosomal disorder caused by missing pieces of one or both ends of chromosome 18. The clinical phenotype of the Ring 18 syndrome depended on the rate and the locality of genetic material lost. Here, we report a 27 years old girl with symptoms including microcephaly, mental and motor retardation, hypotonia, and autoimmune diseases consist of Rheumatoid arthritis, Systemic Lupus Erythematosus, and Crohn's disease. This research contributes to a better understanding of disease and can lead to improvement in diagnosis and treatment.

METHOD AND RESULT

The Chromosomal analysis was performed based on the GTG banding technique on peripheral blood lymphocytes. Karyotype analysis indicated the existence of a Ring chromosome 18 with deletions at 18p11.32 and18q22-2. Following that, the parental karyotype of the affected girl confirmed that Ring 18 was caused by a de novo mistake very early in embryonic development.

CONCLUSION

Ring chromosome 18 is a rare chromosomal disorder that is generally caused by de novo errors very early in the development of the embryo. Previously studies have reported a relationship between autoimmune diseases and Ring 18. Our patient has disclosed specific types of autoimmune diseases, including Systemic Lupus Erythematosus, and Crohn's disease.

A Case of Ring Chromosome 18 with Single Umbilical Artery Detected During Prenatal Period

Fetuses with a single umbilical artery have a risk of increased chromosomal anomalies and congenital malformations. Ring chromosomes are rare and the phenotypic and clinical characteristics of affected individuals show great variability depending on the quantity of the lost critical genes or gains during the formation of the ring or due to mitotic instability. Ring chromosome 18 [r(18)] is characterized by short stature, craniofacial dysmorphism, mental and motor retardation, autoimmune disorders, extremity anomalies, dermal lesions, structural heart malformations, and kidney abnormalities. In this study, the clinical findings of a female patient who had a single umbilical artery in the prenatal period and was diagnosed as de novo r(18) by molecular karyotype analysis were compared with those in the literature. A detailed ultrasonographic examination of the fetus with a single umbilical artery may enable the detection of additional anomalies and thus the early diagnosis of chromosomal anomalies may be possible with prenatal genetic analysis.

Rheumatoid arthritis in an adult patient with mosaic distal 18q-, 18p- and ring chromosome 18

Ring chromosome 18 has a highly variable phenotype, depending on the extent of distal arm deletions. It is most commonly presented as a combination of 18p- and distal 18q- syndrome. IgA deficiency and autoimmune diseases have been previously described in these patients. Seven cases of juvenile rheumatoid arthritis (JRA) have been reported. Here we report the first case of late onset rheumatoid arthritis (RA) in a 32 year old Dominican woman with hypothyroidism, vitiligo, IgA deficiency, interstitial lung disease (ILD), cystic bronchiectasis, and features consistent with ringed 18, 18p- and distal 18q syndrome.  The multiple autoimmune findings in our patient lends further support to the idea of loci on chromosome 18 playing a role in autoimmune disease expression. Late onset RA and ILD in a patient with chromosome 18 abnormalities are novel findings and are additional conditions to be aware of in this population.

Chromosome 18q deletion syndrome with autoimmune diabetes mellitus: putative genomic loci for autoimmunity and immunodeficiency

A girl with 18q deletion syndrome was diagnosed with autoimmune diabetes mellitus and Hashimoto's thyroiditis at the age of 3 yr. In addition, the girl suffered from recurrent infections due to immunoglobulin A and IgG4 deficiency. She was also found to have CD3+CD4+FoxP3+, CD3+CD4+FoxP3+CD25+, and CD3+CD4+CD25+CD127 regulatory T cells deficiency. The exceptional coincidence of the two autoimmune disorders occurring at an early age, and associated with immune deficiency, implies that genes located on deleted 19.4 Mbp region at 18q21.32-q23 (chr18:58,660,699-78,012,870) might play a role in the pathogenesis of autoimmunity leading to β cell destruction and diabetes.

A Rare Association of Monosomy 18p Syndrome and Polyglandular Autoimmune Syndrome Type IIIA

We report a monosomy 18p syndrome in a male patient with polyglandular autoimmune syndrome (PAS) type IIIA. A 34-year-old mentally retarded diabetic male patient with short stature, wide earlaps, old-looking face, straight nasal bone, atrophic mouth, drooping cheeks, full teeth loss, and soft, weak and sparse white hair was admitted to the outpatient endocrinology clinic. Chromosome analysis of the patient revealed 46,XY,del(18)(p11.2). He was also diagnosed with autoimmune thyroiditis, primary hypothyroidism and diabetes mellitus type 1. We concluded that monosomy 18p syndrome may be associated with autoimmune diseases and if this is suspected, patients should be examined for an endocrine deficiency.

Hypothyroidism and levothyroxine-responsive liver dysfunction in a patient with ring chromosome 18 syndrome

BACKGROUND

Ring chromosome 18 [r18] is a rare constitutional chromosomal aberration syndrome, characterized by dysmorphic face, hypoactivity, short stature, and delayed development. Autoimmune thyroiditis and immunoglobulin (Ig) A deficiency are occasionally associated with chromosome-18 deletion syndromes.

SUMMARY

Here, we report a 2-year-old male child with r(18) syndrome and a selective IgA deficiency (<1.6 mg/dL, reference range [rr]: 20-149), who developed hypothyroidism and liver dysfunction. Thyroid function tests (thyroid-stimulating hormone [TSH]: 1031 μIU/mL, rr 0.43-4.0; free triiodothyronine: 0.52 pg/mL, rr 2.37-4.65; free thyroxine: 0.11 ng/dL, rr 1.03-2.00) and positive thyroid antibodies (anti-TSH receptor 1.7 IU/L, cut-off index [coi]: <1.0, antithyroid peroxidase 171 IU/mL, coi <0.3, and antithyroglobulin 2.8 IU/mL, coi <0.3) indicated autoimmune hypothyroidism. Elevated levels of aspartate aminotransferase (AST, 240 IU/L, rr 17-39) and alanine aminotransferase (ALT, 315 IU/L, rr 4-23), but negative antibodies against LKM and mitochondrial M2, suggested no autoimmune hepatitis. Transaminase levels became normalized after he was given levothyroxine therapy to achieve the euthyroid state, but they repeatedly became elevated when levothyroxine was inadvertently discontinued (peak AST=409 IU/L; peak ALT=390 IU/L). A maintenance dose of levothyroxine has effectively maintained the euthyroid state and normalized liver function tests despite no immunosuppressive therapy.

CONCLUSIONS

The r18 patient with autoimmune hypothyroidism and IgA deficiency suffered from idiopathic hepatitis. The liver dysfunction was associated with hypothyroidism that resolved with thyroid hormone treatment. While the former combination has been described, the latter has not. The reason for the development of hepatitis in association with hypothyroidism is unexplained. However, we postulate that it might be related, in ways that are not clear, to the deleted genes of r18.