PMC8385755_01
(A) Pedigree of the WS family with three patients. The black symbols represent the affected members, and the arrow indicates the proband. (B-E) Partial phenotypes of three patients. Proband (II:3) had bilateral finger contractures with mild cutaneous syndactyly (B), dystopia canthorum, and faint synophrys (C); her father (I:1) had dystopia canthorum, bright blue eyes, and prominent nasal root (D); her brother (II:2) had dystopia canthorum, bilateral bright blue eyes, synophrys, white forelock, and prominent nasal root (E).
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F1
We identified a Chinese family with WS (Figure 1A). The proband (II:3) was a 9-year-old girl, who was admitted to our hospital for bilateral finger contractures (Figure 1B). We observed that the girl had dystopia canthorum and faint synophrys (Figure 1C). Tracing back her family history, we found that her mother and sister were unaffected, while her father (I:1) and brother (II:2) had similar facial features, including dystopia canthorum, bright blue eyes (I:1's left eye, and bilateral eyes in II:2), synophrys (I:1 shaping eyebrows), white forelock (I:1 dying hair), and a broad nasal root (Figures 1D,E). We observed that the coverage of exons 1-4 of PAX3 in patients (I:1, II:2, and II:3) was conspicuously lower than that in normal subject (II:1) (Supplementary Figure 1).
(A) The flow diagram of the present research. "no" indicates that we did not detect the causative gene; "yes" indicates that we identified the genetic defect. (B) The Venn diagram of whole-exome sequencing results. Red words represent the affected members; "SNPs" is an abbreviation of single nucleotide polymorphisms; underlines indicate the variants have been reported.
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F2
To confirm our primary diagnosis, we implemented a genetic test program, as shown in Figure 2A, to identify the disease-causing gene of this family and assist in clinical diagnosis. Twenty-one variants in 20 genes were segregated from 326 SNPs, but none seemed a suspicious pathogenic mutation (Figure 2B). Figure 2). Following filtration by OMIM and DECIPHER, we detected a heterozygous gross deletion of PAX3 (10.26kb, chr2: 223153899-223164405) in I:1 (Figure 3).
The visualization of third-generation sequencing result of Chr2: 223143899-223174405 in I:1 by IGV software. Red vertical lines cut out the region of the structural variant, and red words exhibited the details of this structural variant. Black arrows and words point out the exons of PAX3 in the region.
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F3
Figure 2). Following filtration by OMIM and DECIPHER, we detected a heterozygous gross deletion of PAX3 (10.26kb, chr2: 223153899-223164405) in I:1 (Figure 3).
(A) The diagram of primer 1/2 pairs design. Arrows represent primer pairs; red vertical lines cut out the region of the structural variant. (B) Agarose gel electrophoresis results. (C) Sequencing results of sequences amplified according to Primer 1. Red sequence represents deleted sequence; red words indicate genes that correspond to the sequences.
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F4
Agarose gel electrophoresis showed that the deletion co-segregated with the affected individuals, and this deletion was verified by Sanger sequencing (Figure 4).