SCHEDULE 13D/A

GENEDX HOLDINGS CORP

Class A common stock, par value $0.0001 per share · CUSIP: 81663L200

Event date: 2025-08-22

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• CMLS Holdings LLCReported CIK 0001822257

  Shares: 537,285.00 · Class: 1.9%

• C-LSH LLCReported CIK 0001822233

  Shares: 537,285.00 · Class: 1.9%

• M-LSH LLCReported CIK 0001822736

  Shares: 537,285.00 · Class: 1.9%

• Casdin Capital, LLCReported CIK 0001534261

  Shares: 3,007,164.00 · Class: 10.5%

• Casdin Partners Master Fund, L.P.Reported CIK 0001534265

  Shares: 3,007,164.00 · Class: 10.5%

• Casdin Partners GP, LLCReported CIK 0001534260

  Shares: 3,026,411.00 · Class: 10.5%

• Eli CasdinReported CIK 0001534264

  Shares: 3,599,671.00 · Class: 12.4%

• Keith A. MeisterReported CIK 0001307631

  Shares: 3,630,826.00 · Class: 12.5%

• Corvex Management LPReported CIK 0001535472

  Shares: 3,058,629.00 · Class: 10.6%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.