Gollop-Wolfgang complex (GWC) is a rare congenital limb anomaly characterized by tibial aplasia with femur bifurcation, ipsilateral bifurcation of the thigh bone, and split hand and monodactyly of the feet, resulting in severe and complex limb deformities. The genetic basis of GWC, however, has remained elusive. We studied a three-generation family with four GWC-affected family members. An analysis of whole-genome sequencing results using a custom pipeline identified the WNT11 c.1015G>A missense variant associated with the phenotype. In silico modelling and an in vitro reporter assay further supported the link between the variant and GWC. This finding further contributes to mapping the genetic heterogeneity underlying split hand/foot malformations in general and in GWC specifically.

BACKGROUND: Split-hand/foot malformation syndrome is a rare, clinically and genetically het-erogeneous group of limb malformations characterized by absence/hypoplasia and/or median cleft of hands and/or feet. It may occur as an isolated abnormality or it may be associated with a genetic syn-drome.
METHODS: In the present case, isolated split-hand/split-foot malformation was diagnosed by prenatal ultrasound at 24 weeks in a male singleton fetus, with deep median cleft of the right hand, syndactyly and hypoplasia of phalanges in both hands, and oligodactyly of the right foot. During consultation, the father of the fetus revealed that he also had an isolated right foot dysplasia. The parents chose elective termination and autopsy confirmed prenatal ultrasound findings. Genetic testing of the aborted fetus with QF-PCR analysis for common aneuploidies and array comparative genomic hybridization (aCGH) showed a male genomic pattern, without aneuploidies or chromosomal imbalances. Further investigation with next generation sequencing of 49 clinically relevant genes revealed a novel heterozygous FGFR1 mutation c.787_789del (p.Ala263del) in the fetus; the father was heterozygous to the same mutation.
CONCLUSIONS: A novel heterozygous FGFR1 mutation causing split-hand/foot malformation syndrome is reported. Accurate genetic diagnosis allowed detailed counseling to be provided to the couple, including the underlying cause, recurrence risks, and detailed management plan with preimplantation genetic diag-nosis for future pregnancies.

Split hand/foot malformation with long bone deficiency (SHFLD) is a congenital limb anomaly where hands and/or feet cleft and syndactyly are associated with long bone defects, usually involving the tibia. Previously published data reported that 17p13.3 chromosomal duplication, including the BHLHA9 gene, has been associated with the distinct entity, termed SHFLD3 (OMIM 612576), inherited as an autosomal dominant trait. Here, we present a family with three members affected by SHFLD harboring BHLHA9 duplication. We exploited in vitro differentiation system to promote proband\'s skin fibroblasts toward osteoblastic lineage, and we observed a slight but consistent delay in the mineralization pattern. This result possibly suggests an impairment of the osteogenic process in the affected members.

Heterozygous loss-of-function mutations of FGFR1 (fibroblast growth factor receptor 1) cause various disorders including hypogonadotropic hypogonadism with split-hand/foot malformation (HH-SHFM). We examined FGFR1 in four Japanese patients with HH-SHFM (cases 1-4) and the mother of case 4 with HH only. Cases 1 and 2 had heterozygous loss-of-function mutations with no dominant negative effect (c.289G>A, p.[G97S]; and c.2231G>C, p.[R744T]), and case 3 had a splice donor site mutation (c.1663+1G>T). Notably, case 4 had a maternally inherited 8,312 bp microdeletion that involved noncoding exon 1U and impaired FGFR1 expression. Furthermore, consistent with the presence of transcription-related histone marks (e.g., H3K4Me3, H3K4Me1, and H3K27Ac) and multiple transcription factor-binding sites around exon 1U, functional studies demonstrated a marked transactivation function of a 414-bp segment harboring the transcription start site. These results support the relevance of FGFR1 mutations to HH-SHFM, and argue for the presence of the FGFR1 core-promoter elements around exon 1U.

Split-hand/foot malformation (SHFM) is a rare condition which can be either syndromic or nonsyndromic. We report three unrelated pedigrees, one with autosomal dominant (AD) inheritance and the other two with autosomal recessive (AR) pattern. We also briefly review the published reports from India.

The purpose of this series was to identify cases that appeared on sonography to be split-hand/foot malformations (SHFMs) in fetuses and correlate the sonographic findings, including 2-dimensional (2D) and 3-dimensional (3D) sonography, to outcomes. A retrospective review was conducted of sonographic studies from 2002 to 2012 at 2 fetal care centers. Data were collected with respect to the morphologic characteristics of split-hand/foot abnormalities, the utility of 3D sonography, associated anatomic abnormalities, family histories, gestational ages at diagnosis, fetal outcomes, karyotype, and autopsy results. Ten cases were identified with gestational ages ranging from 15 to 29 weeks. Three-dimensional sonography was helpful in defining anatomy in 7 of 9 cases in which it was performed. Bilateral SHFMs were found in 7 cases (3 cases involving both hands and feet, 2 cases isolated to hands, and 2 cases isolated to feet), whereas 3 cases showed unilateral split-hand malformations. Associated anatomic anomalies were present in 6 cases, and 4 of these had recognized syndromes, including 2 with abnormal karyotypes, specifically, del(22q11) and del(7q31). Two cases occurred in the context of a positive family history of SHFM. Three cases were delivered at term, and 7 cases were electively terminated. In conclusion, SHFMs often occur with a broad range of chromosomal abnormalities, single-gene disorders, and other congenital anomalies. Some apparent SHFMs turn out to be other limb anomalies, such as complex syndactyly. Prenatal screening using 2D sonography can identify SHFMs, and 3D sonography often further clarifies them.