Becker and colleagues performed whole exome sequencing on 11 NTM-LD subjects with slender body habitus, pectus excavatum, and scoliosis and found one with mutation of the Fibrillin-1 gene and four (two being sisters) with heterozygous mutations of the Macrophage-Stimulating 1 Receptor (MST1R) gene and in none of 29 NTM-LD patients without pectus excavatum or scoliosis [88]. Here, MST1R is linked to Pectus excavatum.