Vascular Ehlers-Danlos syndrome: A null COL3A1 variant found in a patient with loin pain without marked cutaneous features (case report).

Patients with null variants may have milder vascular Ehlers-Danlos syndrome, presenting with seemingly non-specific complaints and subtle cutaneous features that may be missed. A high index of suspicion and early genetic testing (aided by next-generation sequencing) were crucial for prevention of life-threatening complications in the patient and family members.

THRB Gene Mosaicism Confirmed by Next-Generation Sequencing in a Clinically Symptomatic Infant.

A 4-day-old infant was admitted for neonatal jaundice. He had persistent tachycardia and tachypnea. Initial workup showed a serum free T4 of 75.6 pmol/L (5.87 ng/dL) (reference range: 11.5-28.3 pmol/L; 0.89-2.20 ng/dL) and a nonsuppressed TSH 3.76 mIU/L (reference range: 0.72-11.0 mIU/L). A TRH stimulation test showed an exaggerated TSH response with a peak of 92.1 mIU/L at 30 minutes after TRH injection, which suggested the diagnosis of resistance to thyroid hormone ß syndrome. Sanger sequencing showed a questionable pathogenic variant in the THRB gene with low signal amplitude. Restriction fragment length polymorphism was consistent with its presence. The variant was originally reported as heterozygous. Next-generation sequencing was performed on blood and buccal swab samples of the patient and his parents, which confirmed this de novo mosaic variant NM_000461.5:c.1352T > C p.(Phe451Ser) in the patient but not in his asymptomatic parents. As it was in a mosaic state, only the offspring, but not other first-degree relatives, of the patient would have the risk of inheriting that variant.

Dopamine infusion at typical infusion rates does not cause interference on plasma creatinine assays.

a Objectives: Dopamine is known to cause negative interference on enzymatic creatinine measurement. However, its effect on the Jaffe reaction, and its concentration required to interfere with enzymatic reactions, remain uncertain. This study was designed to study the interference of stable dopamine infusion on Jaffe and enzymatic creatinine assays, as well as the effect of dopamine infusion drip arm contamination on both creatinine assays. b Design and Methods: For the first part of the study, dopamine was spiked into pooled plasma samples at different concentrations to mimic the scenario of patients on dopamine infusion at an infusion rate between 2 and 20 µg/kg/min. For the second part, dopamine preparation of 2 g/L (same as the preparation used clinically) was mixed with pooled plasma samples at different proportions to mimic drip arm contamination. Creatinine concentrations were measured using Jaffe and enzymatic reactions. c Results: The first part showed that creatinine measurements were not interfered by dopamine infusion at an infusion rate between 2 and 20 µg/kg/min. The second part showed that dopamine could negatively interfere with enzymatic creatinine assays, even with minute drip arm contamination. The effect on the Jaffe reaction was less significant. d Discussion: Creatinine concentration could be reliably measured by Jaffe or enzymatic reactions if samples are from venous access sites other than the site of dopamine infusion. When dopamine interference on enzymatic creatinine assays is suspected, using the Jaffe reaction to cross-check may provide additional useful information.