The goal of this study is to develop a biorepository to store pediatric biospecimen from nephrology cohorts for on-going and future research studies. These studies plan to advance the state of science in the hopes to develop novel diagnostic approaches and identify therapeutic targets to prevent and/or treat pediatric disease involving the kidneys.

The purpose of this study is to learn how well a new mobile app helps families manage their child's nephrotic syndrome. We will be asking what parents think of the new app and how we can improve the design of the app. We will look for 60 parents to participate in the study, from 4 children's kidney clinics in the United States. The study will last 12 months. Participants will be asked to check their child's urine protein levels at home daily and answer surveys. If participants are randomly assigned to the mobile app study arm, they will be asked to use the app. The risks associated with participating in this study include loss of privacy and breach of confidentiality. There are no anticipated benefits to your child from participating in the study, but we hope that in the future the app will help families manage nephrotic syndrome. The alternative is to not participate in this study. Participants will be compensated for their participation in the study.

A device called the "Liposorber LA-15 System" has been approved by the United States Food and Drug Administration for treating kids with focal segmental
glomerulosclerosis (FSGS). The "Liposorber LA-15 System" can only be used if other treatment options, like drugs, don't work or can't be used, but the kidneys are still working okay. It can also be used if the subject has had a kidney transplant and the FSGS comes back after the transplant. Although the Liposorber System can be used for FSGS, we are not sure how well the Liposorber System works. So, we are doing this study to find out how well the treatment works.

In this research study, there will be up to 5 children who have FSGS enrolled at MUSC. Subjects will come back for up to 12 treatments over 9 weeks and then 5 visits to their study doctor over the next 2 years.