Linkage localization of Börjeson‐Forssman‐Lehmann syndrome

Abstract

Börjeson-Forssman-Lehmann syndrome (BFLS) is a form of X-linked mental retardation (XLMR) with characteristic minor physical anomalies. It has no biochemical or cytogenetic markers. Heterozygous females may be entirely normal or may have mild-to-moderate manifestations. We studied 41 individuals from one family with BFLS for linkage on the X chromosome. The highest lod scores were 2.32 with DXS10 and 2.24 with DXS51, both at a theta = 0.0. A single recombinant was found between HPRT and BFLS. These results suggest that the BFLS locus is on the distal portion of Xq. Previously reported linkage studies in families with XLMR have not shown linkage with DXS10. This study suggests that one of the several X chromosome loci whose dysfunction is associated with mental retardation is located on distal Xq.

New X‐linked syndrome of mental retardation, gynecomastia, and obesity is linked to DXS255

“…They did not have hypermetropia or cataracts in later life and did not have elongated ear lobes. Our impression was that they had a separate clinical entity, and this was confirmed by DNA linkage studies suggesting regional localisation of the gene in this family to Xp22.1-q22, whereas provisional localisation of the gene for the BFLS is Xq26-27 [Turner et al, 1989;Mathews et al, 1989a; bl. The observed large size, coarse face, and small hands and feet are also seen in the Simpson-Golabi-Behmel syndrome, but this has not been reported with gynecomastia and usually has other findings including midline defects, polydactyly, and supernumerary nipples [Golabi and Rosen, 1984;Behmel et al, 1984;Neri et al, 19881. Other studies have identified kindred with X-linked mental retardation in which gene localisation may be near the centromere.…”

Novel PHF6 mutation p.D333del causes Borjeson-Forssman-Lehmann syndrome

“…8 BFLS has been mapped by linkage analysis to the chromosomal region Xq26-q27 with the highest lod score between markers DXS10 and DXS51. [9][10][11] The candidate gene region was refined later by inclusion of additional family members and by an improved genetic map of this region. 12 The highest lod score was then calculated for the interval between the markers DXS425 and DXS105.…”

Behavioural phenotype in Börjeson‐Forssman‐Lehmann syndrome

“…(1962) already considered the syndrome to follow an X‐linked recessive pattern of inheritance. Linkage studies confirmed localisation on the X‐chromosome at Xq27 (Mathews et al. 1989; Turner et al.…”

“…Börjeson et al (1962) already considered the syndrome to follow an X-linked recessive pattern of inheritance. Linkage studies confirmed localisation on the X-chromosome at Xq27 (Mathews et al 1989;Turner et al 1989), and in 2002 mutations were identified in the PHF6 gene (Lower et al 2002). This is a zinc finger gene that may be involved in transcription (Lower et al 2002) and cell growth and proliferation (Gécz et al 2006).…”