Identifying a novel SRCAP variant in floating-harbor syndrome and prenatal genetic diagnosis in this Chinese family: A case report

Figure 1 Clinical features of the patient. A: Physical findings include a short philtrum, long eyelashes, a prominent nose with narrow nasal root and broad nasal tip, dental malocclusion, and clubbing of fingers; B: A pedigree of the analyzed family in this study. The proband with Floating-Harbor syndrome is indicated by an arrow; C: Protein sequence alignment of human SRCAP with orthologues from mouse, rat and bovine, showing that threonine at position 2412 are evolutionary conserved (outlined in red); D and E: Structural models of the SRCAP protein predicted with AlphaFold3. SRCAP structures of wild-type and p.Thr2412fs are shown, respectively. The box specified residue at position 2412 highlighted as sticks; F: Sanger sequences of the SRCAP gene variant in the proband, the fetus and their parents. The frameshift variant c.7235delinsGT (p.Thr2412fs) was detected in the proband (III-1), but not detected in the fetus (III-2), father (II-1) and mother (II-2).

Figure 2 Intron-exon structure bearing domain structure of the SRCAP gene. A: The ratio of variant types of SRCAP in the Human Gene Mutation database; B: Locations of c.7235delinsGT (p.Thr2412fs) variant found in our proband are shown. HSA, Helicase-SANT-associated domain.