A familial case of Muenke syndrome. Diverse expressivity of the FGFR3 Pro252Arg mutation--case report and review of the literature.

Muenke is a fibroblast growth factor receptor 3 (FGFR-3)-associated syndrome, which was first described in late 1990 s. Muenke syndrome is an autosomal dominant disorder characterized mainly by coronal suture craniosynostosis, hearing impairment and intellectual disability. The syndrome is defined molecularly by a unique point mutation c.749C > G in exon 7 of the FGFR3 gene which results to an amino acid substitution p.Pro250Arg of the protein product. Despite the fact that the mutation rate at this nucleotide is one of the most frequently described in human genome, few Muenke familial case reports are published in current literature. We describe individuals among three generations of a Greek family who are carriers of the same mutation. Medical record and physical examination of family members present a wide spectrum of clinical manifestations. In particular, a 38-year-old woman and her father appear milder clinical findings regarding craniofacial characteristics compared to her uncle and newborn female child. This familial case illustrates the variable expressivity of Muenke syndrome in association with an identical gene mutation.

Successful hematopoietic stem cell transplantation in 2 children with X-linked chronic granulomatous disease from their unaffected HLA-identical siblings selected using preimplantation genetic diagnosis combined with HLA typing.

We report 2 children with X-linked chronic granulomatous disease (X-CGD) who underwent hematopoietic stem cell transplantation (HSCT) using grafts from their siblings selected before implantation to be both unaffected and HLA-matched donors. Preimplantation genetic diagnosis (PGD) along with HLA-typing were performed on preimplantation embryos by single-cell multiplex polymerase chain reaction using informative short tandem repeat markers in the HLA locus together with the gene region containing the mutations. Two singleton pregnancies resulted from the intrauterine transfer of selected embryos; these developed to term, producing 1 healthy female and 1 X-CGD carrier female, which are HLA-identical siblings to the 2 affected children. Combined grafts of umbilical cord blood (UCB) and bone marrow (BM) stem cells were administered to the recipients after myeloablative (MA) conditioning at the ages of 4.5 years and 4 years, respectively. Both patients are well, with complete donor hematopoietic and immunologic reconstitution, at 18 and 13 months posttransplantation, respectively. This report demonstrates that HSCT with HLA-matched sibling donors created by PGD/HLA typing of in vitro fertilized embryos is a realistic therapeutic option and should be presented as such to families with children who require a non-urgent HSCT but lack an HLA-genoidentical donor.

Birth of a healthy histocompatible sibling following preimplantation genetic diagnosis for chronic granulomatous disease at the blastocyst stage coupled to HLA typing.

OBJECTIVE: To perform preimplantation genetic diagnosis (PGD) for chronic granulomatous disease with simultaneous HLA typing in a family case with an affected male child, with the aim of selecting unaffected and HLA-matched embryos to act as donors for hematopoietic stem cell transplantation from umbilical cord blood. METHODS: A flexible, indirect HLA haplotyping protocol, based on single-cell multiplex PCR analysis of multiple polymorphic short tandem repeat (STR) markers within the human HLA complex, was optimized for the simultaneous amplification of the informative STR markers together with the gp91-phox gene region containing the mutation and the sexing marker amelogenin. Detection of the c.469C>T disease mutation was performed by minisequencing. Biopsy was performed at the blastocyst stage on day 5 by removal of trophectoderm cells. RESULTS: A total of 11 blastocysts were biopsied on day 5 and a successful result for the informative STR markers and for the mutation detection was obtained for all 11 blastocyst samples. Two healthy and HLA-matched embryos were identified and transferred resulting in a singleton pregnancy. The results of the PGD were confirmed following standard prenatal diagnosis, and cord blood hemopoietic stem cells were obtained from the newborn for subsequent transplantation into the affected sibling. CONCLUSIONS: This study demonstrates the feasibility and first successful application of this complex PGD approach as a therapeutic option in families with children affected with X-linked chronic granulomatous disease.

CFTR DeltaF508 mutation detection from dried blood samples in the first trimester of pregnancy: a possible routine prenatal screening strategy for cystic fibrosis?

OBJECTIVE: The implementation and evaluation of a proposed wide-scale prenatal screening strategy, based on DNA isolated from dried blood spots in the first trimester of pregnancy, for the early detection of pregnancies at risk for cystic fibrosis (CF). METHODS: The screening was performed in conjunction with routine biochemical marker screening for Down's syndrome risk in the first trimester of pregnancy. DNA was isolated from 1,233 dried blood spots and analyzed for the presence of the CF transmembrane regulator DeltaF508 mutation. Women carriers were offered and accepted the option for additional full testing of their partners in order to assess the risk for the fetus. RESULTS: All 1,233 samples were successfully analyzed, identifying 23 DeltaF508 carriers, corresponding to a DeltaF508 carrier rate of approximately 1/55 (1.8%). All partners of the women carriers were further tested without revealing any need for further prenatal testing in this group. CONCLUSIONS: This study reveals the relatively high frequency of the DeltaF508 CF mutation in the Greek population. More importantly, we demonstrate that the proposed prenatal screening strategy, based on the ease and cost-effectiveness of the analysis for the detection of a single common mutation, can be considered as a feasible and practical approach for wide-scale prenatal screening for CF, following the sequential model. It is applied early on in pregnancy, allowing for the timely management of families at risk for the corresponding genetic disorders. Finally, it can easily be extended to include screening for other common genetic disorders in specific population groups.