Greig cephalopolysyndactyly syndrome with dysgenesis of the corpus callosum in a Bedouin family

The Development of Human Genetics at the National Research Centre, Cairo, Egypt: A Story of 50 Years

This article describes my experiences over more than 50 years in initiating and maintaining research on human genetics and genomics at the National Research Centre in Cairo, Egypt, from its beginnings in a small unit of human genetics to the creation of the Center of Excellence for Human Genetics. This was also the subject of a lecture I gave at the 10th Conference of the African Society of Human Genetics, held in Cairo in November 2017, after which Professor Michèle Ramsay, president of the society, suggested that I write an autobiographical article for the Annual Review of Genomics and Human Genetics. I hope that I succeeded in the difficult assignment of summarizing the efforts of a researcher from a developing country to initiate and maintain the rapidly advancing science of human genetics and genomics in my own country and make contributions to the worldwide scientific community.

The spectrum of hand and foot malformations in patients with Greig cephalopolysyndactyly

PURPOSE

Greig cephalopolysyndactyly (GCPS) (OMIM 175700), a rare autosomal dominant disorder, is characterized by a distinct combination of craniofacial, hand and foot malformations. The hand and foot malformations often require orthopedic assessment and treatment. The disorder is caused by point mutations or deletions in the GLI3 gene, located on chromosome 7p14.3. Herewith, we review the hand and foot malformations in a cohort of 13 patients referred for genetic testing.

METHODS

We reviewed the medical files of 13 patients with GCPS seen at the Center for Human Genetics in Leuven between 2003 and 2005. Clinical, molecular and radiological findings, when available, were recorded.

RESULTS

We identified six different point mutations in the GLI3 gene, two microdeletions and three larger chromosomal deletions. In the hands, preaxial polydactyly was never observed, but the malformations included postaxial polydactyly, broad thumbs, clinodactyly of the thumbs and various degrees of syndactyly. In the feet the spectrum of malformations included preaxial polydactyly, postaxial polydactyly, different degrees of syndactyly and broad halluces. Syndactyly of the toes and hallux abnormalities were present in all patients. Most frequently, syndactyly was present between toes 1-2-3. The broadening of the hallux was either due to a complete or partial duplication of the first toe or to broadening of the distal phalanx. Mental retardation was found in three cases and was associated with a large chromosomal deletion of the GLI3 region.

CONCLUSION

We found the classic hand and foot malformations associated with GCPS in our cohort of patients. Patients with a large chromosomal deletion had mental retardation, but no structural brain anomalies were found.

Variable phenotype in Greig cephalopolysyndactyly syndrome: clinical and radiological findings in 4 independent families and 3 sporadic cases with identified GLI3 mutations

Greig cephalopolysyndactyly (GCPS) (OMIM 175700) is an autosomal dominant disorder characterized by a distinct combination of craniofacial, hand and foot malformations. In this report, clinical and radiological findings of 12 patients with GCPS derived from 4 independent families and 3 sporadic cases with documented GLI3 mutations are presented with particular emphasis on inter- and intrafamilial variability. In a particularly instructive family in which 9 members of 4 generations could be studied clinically and molecularly, a missense mutation (R625W) is transmitted and shows a partially penetrant pattern. In a branch of the family, the GCPS phenotype skips a generation via a normal female carrier without clinical signs providing evidence that GCPS does not always manifest full penetrance as generally supposed.