2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-Natural Medical History Study of Patients with STAC3 Disorder from a Single Center

Pdf Summary

This document provides an overview of a natural medical history study conducted on patients with STAC3 disorder, also known as Native American Myopathy. The study aimed to analyze the clinical and molecular features of patients with STAC3 disorder, with a particular focus on the Lumbee founder variant.<br /><br />STAC3 disorder is a rare autosomal recessive condition that was initially observed in patients from the Lumbee tribe of North Carolina but has since been identified in various populations worldwide. The disorder is characterized by a range of features, including congenital myopathy, musculoskeletal and palatal anomalies, short stature, facial dysmorphisms, feeding difficulties, respiratory impairment, and malignant hyperthermia.<br /><br />The study included a total of 22 patients with a clinical or molecular diagnosis of STAC3 disorder, all of whom had Native American ancestry. The average age at molecular diagnosis was 26 months, and all patients were found to be homozygous for the c.851G>C variant, which is the founder variant in the Lumbee population.<br /><br />The study identified several common physical features among the patients, including hypotonia, myopathic facies, ptosis, dysmorphic features, micrognathia, and palatal abnormalities. Other outcomes observed in the study included feeding difficulties, respiratory impairment, receptive or expressive speech delay, delayed motor milestones, hearing loss, and the need for physical, occupational, or speech therapy.<br /><br />The study also highlighted the potential prenatal and neonatal complications associated with STAC3 disorder, such as prenatal drug or alcohol exposure, contractures on ultrasound, and neonatal ICU stays.<br /><br />Overall, this study provides valuable insights into the natural history and clinical features of STAC3 disorder, particularly in individuals with the Lumbee founder variant. The findings can help improve the care and management of patients with this rare disorder and provide guidance to patients, families, and medical providers.

Asset Subtitle

Presenting Author - Kristen Lancaster, MD; Co-Author - Cynthia M. Powell, MD, MS, FACMG;

Meta Tag

Respiratory System

Phenotype

Natural History

Musculoskeletal system

Genotype-Phenotype Correlations

Dysmorphology

Congenital Anomaly

Clinical History

Co-Author Cynthia M. Powell, MD, MS, FACMG

Presenting Author Kristen Lancaster, MD

Keywords

natural medical history study

STAC3 disorder

Native American Myopathy

clinical features

molecular features

Lumbee founder variant

autosomal recessive condition

congenital myopathy

musculoskeletal anomalies

palatal anomalies