Segmental undergrowth is associated with pathogenic variants in vascular malformation genes: A retrospective case-series study.

Segmental overgrowth has been widely described in patients with congenital vascular anomalies. However, segmental undergrowth has been poorly characterized, and no large series of patients have been published. We present the clinical and molecular characteristics a cohort of 37 patients with vascular malformations and segmental undergrowth. True undergrowth was only considered when the musculoskeletal system was involved to avoid confusion with other causes of segmental reduction, as in lipodystrophy or the long-term osteopenia seen in patients with Servelle-Martorell syndrome. Deep high-throughput sequencing was performed in tissue samples from 20 patients using a custom panel. We identified three groups: undergrowth associated with (1) venous, (2) capillary-venous, and (3) lymphatic-capillary-venous malformations. Congenital or early childhood onset undergrowth can occur with or without associated overgrowth. Different likely pathogenic or pathogenic variants were detected in 13 of 20 (65%) tissue samples in the PIK3CA, TEK, GNAQ, or GNA11 genes. In conclusion, the eponymous Servelle-Martorell syndrome should not be used as a synonym for undergrowth. Segmental undergrowth should be considered a characteristic associated with vascular malformations. Patients with PIK3CA variants show all different combinations of overgrowth and undergrowth. Thus, the term PROS (PIK3CA-related overgrowth spectrum) does not cover the entire spectrum.

The predictive role of early activation of natural killer cells in septic shock.

Recently, several studies about the role of natural killer (NK) cells in sepsis have been highlighted. In an earlier study, we characterized the abnormalities of circulating lymphocytes in 52 patients with septic shock during the first 28 days in the intensive care unit. Our results confirm and expand some previous reports. We found that patients who did not survive exhibited less NK cell (CD3-CD56⁺) depletion than survivors and that these NK cells expressed CD69⁺ and CD57⁺. These data demonstrate that NK cells are key participants in septic shock because patients who survived have more depletion and expressed less early activation and differentiation.