Protein disulfide isomerase A6 (PDIA6) is an unfolded protein response (UPR)‐regulating protein. PDIA6 regulates the UPR sensing proteins, Inositol requiring enzyme 1, and EIF2AK3. Biallelic inactivation of the two genes in mice and humans resulted in embryonic lethality, diabetes, skeletal defects, and renal insufficiency. We recently showed that PDIA6 inactivation in mice caused embryonic and early lethality, diabetes and immunodeficiency. Here, we present a case with asphyxiating thoracic dystrophy (ATD) syndrome and infantile‐onset diabetes. Whole exome sequencing revealed a homozygous frameshift variant in the PDIA6 gene. RNA expression was reduced in a gene dosage‐dependent manner, supporting a loss‐of‐function effect of this variant. Phenotypic correlation with the mouse model recapitulated the growth defect and delay, early lethality, coagulation, diabetes, immunological, and polycystic kidney disease phenotypes. In general, the phenotype of the current patient is consistent with phenotypes associated with the disruption of PDIA6 and the sensors of UPR in mice and humans. This is the first study to associate ATD to the UPR gene, PDIA6. We recommend screening ATD cases with or without insulin‐dependent diabetes for variants in PDIA6.

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Highlights Osteoid osteoma of scapular glenoid is rare. The presence of lesions in unusual locations along with atypical history could misinterpret the diagnosis. Osteoid osteoma should be considered in differential diagnosis of chronic shoulder pain if no response to initial treatment.

Teratomas or Germ cell tumours (GCTs) are interesting because of their obscure origin, bizarre microscopic appearance and unpredictable behaviour. Mediastinal teratoma is a slowly growing and rare tumour found in children that is diagnosed incidentally in asymptomatic patients. Most of the symptoms are related to mass compression effects such as chest pain, cough, respiratory distress and dysphagia. We report a 5-year-old male child who presented with a history of foreign body ingestion, sternal and left upper quadrant pain and vomiting without respiratory distress. The patient was incidentally found to have an anterior mediastinal mass compressing the right atrium and was diagnosed by histopathological examination as having a mature cystic teratoma of the mediastinum. The patient was successfully treated by the surgical resection of the tumour.