👤 Albert Schinzel

Few patients with interstitial deletions in the distal long arm of chromosome 14 have been reported, and these patients showed rather indistinct features, including growth and mental retardation and phenotypic alterations. We describe a de novo 14q interstitial deletion in a 6-year-old boy with dysmorphic facial traits such as hypertelorism, short and narrow palpebral fissures, broad nose with anteverted nostrils, long philtrum, thin upper lip with cupid's bow, prominent and everted lower lip, mildly low-set ears, as well as moderate developmental delay and mild mental retardation. Array-CGH mapped the deletion to the region 14q24.3 to 14q31.3, including 13.11 Mb, proximal to the imprinted genomic region of 14q32. This mild phenotypic presentation suggests that the deleted segment does not contain essential genes for early organ development. Twenty-two genes with known functions, including Neurexin III (NRXN3, OMIM 600567), map to the region deleted in the propositus. Show less

Long-term observations of individuals with the so-called Langer-Giedion (LGS) or tricho-rhino-phalangeal type II (TRPS2) are scarce. We report here a on follow-up of four LGS individuals, including one first described by Andres Giedion in 1969, and review the sparse publications on adults with this syndrome which comprises ectodermal dysplasia, multiple cone-shaped epiphyses prior to puberty, multiple cartilaginous exostoses, and mostly mild intellectual impairment. LGS is caused by deletion of the chromosomal segment 8q24.11-q24.13 containing among others the genes EXT1 and TRPS1. Most patients with TRPS2 are only borderline or mildly cognitively delayed, and few are of normal intelligence. Their practical skills are better than their intellectual capability, and, for this reason and because of their low self-esteem, they are often underestimated. Some patients develop seizures at variable age. Osteomas on processes of cervical vertebrae may cause pressure on cervical nerves or dissection of cerebral arteries. Joint stiffness is observed during childhood and changes later to joint laxity causing instability and proneness to trauma. Perthes disease is not rare. Almost all males become bald at or soon after puberty, and some develop (pseudo) gynecomastia. Growth hormone deficiency was found in a few patients, TSH deficiency so far only in one. Puberty and fertility are diminished, and no instance of transmission of the deletion from a non-mosaic parent to a child has been observed so far. Several affected females had vaginal atresia with consequent hydrometrocolpos. Show less

On the basis of the Human Cytogenetic Database, a computerized catalog of the clinical phenotypes associated with cytogenetically detectable human chromosome aberrations, we collected from the literature 102 cases with chromosomal aberrations and split hand/foot malformation or absent fingers/toes. Statistical analysis revealed a highly significant association (P<0.001) between the malformation and the chromosomal bands 4q32-q35, 5q15, 6q16-q22 and 7q11.2-q22 (SHFM1). Considering these findings, we suggest additional SHFM loci on chromosome 4q, 6q and probably 5q. The regions 4q and 6q have already been discussed in the literature as additional SHFM loci. We now show further evidence. In the proposed regions, there are interesting candidate genes such as, on 4q: HAND2, FGF2, LEF1 and BMPR1B; on 5q: MSX2, FLT4, PTX1 and PDLIM7; and on 6q: SNX3, GJA1, HEY2 and Tbx18. Show less

Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogeneous autosomal recessive disorder characterized by retinitis pigmentosa, polydactyly, obesity, hypogenitalism, mental retardation, and renal anomalies. To detect linkage to BBS loci, 29 BBS families, of mixed but predominantly European ethnic origin, were typed with 37 microsatellite markers on chromosomes 2, 3, 11, 15, 16, and 17. The results show that an estimated 36-56% of the families are linked to the 11q13 chromosomal site (BBS1) previously described by M. Leppert et al. (1994, Nature Genet. 7, 108-112), with the gene order cen-D11S480-5 cM-BBS1-3 cM-D11S913/D11S987-qter. A further 32-35% of the families are linked to the BBS4 locus, reported by R. Carmi et al. (1995, Hum. Mol. Genet. 4, 9-13) in chromosomal region 15q22.3-q23, with the gene order cen-D15S125-5 cM-BBS4-2 cM-D15S131/D15S204-qter. Three consanguineous BBS families are homozygous for three adjacent chromosome 15 markers, consistent with identity by descent for this region. In one of these families haplotype analysis supports a localization for BBS4 between D15S131 and D15S114, a distance of about 2 cM. Weak evidence of linkage to the 16q21 (BBS2) region reported by A. E. Kwitek-Black et al. (1993, Nature Genet. 5, 392-396) was observed in 24-27% of families with the gene order cen-D16S408-2 cM-BBS2-5 cM-D16S400. A fourth group of families, estimated at 8%, are unlinked to all three of the above loci, showing that at least one other BBS locus remains to be found. No evidence of linkage was found to markers on chromosome 3, corresponding to the BBS3 locus, reported by V. C. Sheffield et al. (1994, Hum. Mol. Genet. 3, 1331-1335), or on chromosome 2 or 17, arguing against the involvement of a BBS locus in a patient with a t(2;17) translocation. Show less