Welcome to Live, Laugh, Lucas friends! The purpose of this project is to give a sneak peek at what it's like living with and overcoming disability. This video is the introduction to our amazing little boy, Lucas! Lucas has had global developmental delay since birth and has yet to be diagnosed. Here is his 2021 genetic summary that you'll here in the video: Lucas is a 3 year old male with central hyptonia, peripheral spasticity, and developmental delays. His muscle biopsy was largely non-diagnostic, however, it did confirm that the likely pathogenic variant in MT-CO3 is only present at 10.7% in his muscle tissue. We reviewed that this suggests that Lucas is a low level carrier of this mutation and it is not contributing to his symptoms, as symptoms are rarely seen with heteroplasmy of less than 25% when an affected tissue is tested (i.e muscle). He underwent genetic testing with microarray, whole exome sequencing, and testing for spinal muscular atrophy which were normal. He is known to carry 3 variants in his mitochondrial DNA 1.) MT-CO3 The muscle testing confirms that Lucas is a low level carrier of this pathogenic MT- CO3 mutation, but our suspicion that it is contributing to his symptoms is low. Given he carries this mutation at roughly 11% in his muscle, this may contribute to the mild reduction in complex 4 activity, but the level of activity itself is considered within normal limits. 2.) MT-ND2 Given the heteroplasmy distribution at around 45% in multiple tissues in Lucas and low levels (less than 15%) in his unaffected mother, we cannot exclude this variant at this time and thus it remains a variant of uncertain significance. While complex 1 activity was within normal limits, there are some instances of complex 1 mutation that do not cause detectable deficiencies , but rather cause an assembly defect. More testing on this variant is recommended. 3.) MT-ND5 This variant was classified as likely benign by CHOP's lab. Since it is also seen in his asymptomatic mother, our suspicion this variant is contributing to his symptoms is low. No additional testing for this variant is recommended at this time. We remain unable to provide an exact genetic etiology for Lucas's symptoms at this time. It is possible that his symptoms could be due to a mitochondrial disease, however, frank evidence of mitochondrial disease was not present on muscle biopsy testing. Thanks for watching and be sure to check out our other videos to follow along with all the progress Lucas has made!

• published: 18 Jan 2023
• views: 95