Biallelic ATP2B1 variants as a likely cause of a novel neurodevelopmental malformation syndrome with primary hypoparathyroidism

ATP2B1 encodes plasma membrane calcium-transporting-ATPase1 and plays an essential role in maintaining intracellular calcium homeostasis that regulates diverse signaling pathways. Heterozygous de novo missense and truncating ATP2B1 variants are associated with a neurodevelopmental phenotype of variable expressivity. We describe a proband with distinctive craniofacial gestalt, Pierre-Robin sequence, neurodevelopmental and growth deficit, periventricular heterotopia, brachymesophalangy, cutaneous syndactyly, and persistent hypocalcemia from primary hypoparathyroidism. Proband-parent trio exome sequencing identified compound heterozygous ATP2B1 variants: a maternally inherited splice-site (c.3060+2 T > G) and paternally inherited missense c.2938 G > T; p.(Val980Leu). Reverse-transcription-PCR on the proband's fibroblast-derived mRNA showed aberrantly spliced ATP2B1 transcripts targeted for nonsense-mediated decay. All correctly-spliced ATP2B1 mRNA encoding p.(Val980Leu) functionally causes decreased cellular Ca2+ extrusion. Immunoblotting showed reduced fibroblast ATP2B1. We conclude that biallelic ATP2B1 variants are the likely cause of the proband's phenotype, strengthening the association of ATP2B1 as a neurodevelopmental gene and expanding the phenotypic characterization of a biallelic loss-of-function genotype.

De novo variants in ATP2B1 lead to neurodevelopmental delay

Calcium (Ca²⁺) is a universal second messenger involved in synaptogenesis and cell survival; consequently, its regulation is important for neurons. ATPase plasma membrane Ca²⁺ transporting 1 (ATP2B1) belongs to the family of ATP-driven calmodulin-dependent Ca²⁺ pumps that participate in the regulation of intracellular free Ca²⁺. Here, we clinically describe a cohort of 12 unrelated individuals with variants in ATP2B1 and an overlapping phenotype of mild to moderate global development delay. Additional common symptoms include autism, seizures, and distal limb abnormalities. Nine probands harbor missense variants, seven of which were in specific functional domains, and three individuals have nonsense variants. 3D structural protein modeling suggested that the variants have a destabilizing effect on the protein. We performed Ca²⁺ imaging after introducing all nine missense variants in transfected HEK293 cells and showed that all variants lead to a significant decrease in Ca²⁺ export capacity compared with the wild-type construct, thus proving their pathogenicity. Furthermore, we observed for the same variant set an incorrect intracellular localization of ATP2B1. The genetic findings and the overlapping phenotype of the probands as well as the functional analyses imply that de novo variants in ATP2B1 lead to a monogenic form of neurodevelopmental disorder.

Chemical composition and antimicrobial activities of the essential oils from three ecotypes of Zataria multiflora

Background:

Zataria multiflora Boiss. is a traditional and popular spice in Iran. The effects of 3 ecotypes (ECTPs) of Z. multiflora essential oils (EOs) against most common causes of food-borne and nosocomial infections were evaluated.

Materials and Methods:

The antimicrobial activities of the EOs were examined by broth microdilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). The chemical compositions of the EOs from 3 ECTPs of Z. multiflora have been analyzed by gas chromatography–mass spectrometry.

Results:

Analysis of the EOs indicated that 3 chemotypes were present in Z. multiflora, including carvacrol, thymol-carvacrol, and linalool, whereas previous studies have only found carvacrol and thymol. Inhibition studies showed that the tested EOs entirely inhibited the growth of yeasts at concentrations of less than 1 μL/mL. Moreover, the oils exhibited significant bacteriostatic and bactericidal activities against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.12 to 8 μL/mL.

Conclusion:

These results suggest that the EOs from Z. multiflora should be investigated further for possible use in antimicrobial products and food preservatives.