Successful kidney transplantation in a patient with neonatal-onset ILNEB

Integrin mutations in blistering skin diseases and related genetically engineered mouse models

As major receptors for cellular adhesion, integrins in the epidermis are critical to maintain skin integrity. Integrins α6β4 and α3β1 are among the most highly and widely expressed integrins in the skin. Perhaps not surprisingly, mutation in subunits associated with these integrins cause variations of a blistering skin disease called junctional epidermolysis bullosa (JEB), which is characterized by blisters that form between the epidermis and dermis of the skin. This review highlights how the differences in structural roles and functions for these epidermal integrins lead to distinct JEB phenotypes resulting from their absence. Additionally, much has been learned by using genetically engineered mouse models, which are featured throughout the review, as they closely resemble the disorders of human patients that harbor analogous mutations.

A novel ITGA3 homozygous splice mutation in an ILNEB syndrome child with slow progression

BACKGROUND AND AIMS

ILNEB (interstitial lung disease, nephrotic syndrome, epidermolysis bullosa) syndrome is caused by ITGA3 mutations. Demises usually happened at infancy. This study reports a complete ILNEB syndrome child with slow disease progression.

MATERIALS AND METHODS

Clinical data and related specimens were collected. Genomic DNA was extracted for genetic sequencing. Integrin α3 expression was detected by western blotting and immunofluorescence staining.

RESULTS

The patient was male. He experienced recurrent rashes shortly after birth. His sparse eyebrows and eyelashes gradually lost. The patient was vulnerable to respiratory infections and had recurrent fever after vaccine immunization after 4 years. He was found with nephrotic syndrome and polycystic renal dysplasia at 8 years and progressed to end-stage renal disease at 12 years. A chest Computed Tomography revealed intestinal lung disease at 8 years. Continuous oxygen supplementation was needed at 13 years. Counts of lymphocyte subsets revealed elevated percentage of double-negative T cells and activated T cells. Next-generation sequencing revealed a novel homozygous splice mutation c.2219 + 4A > Cin ITGA3 that was predicted to be deleterious. The mutation resulted in exon17 skipping with the loss of 80 bp in the mRNA. The aberrant integrin α3 mRNA level was lower compared to the healthy control. Integrin α3 protein was not detected in urine epithelial cells and skin of the patient.

CONCLUSIONS

We report a patient harboring a novel ITGA3 homozygous splice mutation who presented with complete ILNEB syndrome but slow disease progression. Immune disorders were suspected.

First patient with ILNEB syndrome due to pathogenic variants in ITGA3 surviving to adulthood

Interstitial Lung disease, Nephrotic syndrome and Epidermolysis Bullosa, also referred to as ILNEB syndrome is an extremely rare autosomal recessive condition, caused by pathogenic variants in ITGA3. 11 patients have previously been diagnosed with ILNEB syndrome of whom 7 died in infancy or early childhood. We report the only patient with ILNEB syndrome who survived past adolescence, partly due to a double lung transplant. Additionally, our patient showed oral, nasal and gynecological symptoms not previously reported in patients with ILNEB syndrome.