The CCR5-Delta32 deletion obliterates the CCR5 chemokine and the human immunodeficiency virus (HIV)-1 coreceptor on lymphoid cells, leading to strong resistance against HIV-1 infection and AIDS. A genotype survey of 4,166 individuals revealed a cline of CCR5-Delta32 allele frequencies of 0%-14% across Eurasia, whereas the variant is absent among native African, American Indian, and East Asian ethnic groups. Haplotype analysis of 192 Caucasian chromosomes revealed strong linkage disequilibrium between CCR5 and two microsatellite loci. By use of coalescence theory to interpret modern haplotype genealogy, we estimate the origin of the CCR5-Delta32-containing ancestral haplotype to be approximately 700 years ago, with an estimated range of 275-1,875 years. The geographic cline of CCR5-Delta32 frequencies and its recent emergence are consistent with a historic strong selective event (e.g. , an epidemic of a pathogen that, like HIV-1, utilizes CCR5), driving its frequency upward in ancestral Caucasian populations.

Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities. Three subtypes have been described: TRPS I, caused by mutations in the TRPS1 gene on chromosome 8; TRPS II, a microdeletion syndrome affecting the TRPS1 and EXT1 genes; and TRPS III, a form with severe brachydactyly, due to short metacarpals, and severe short stature, but without exostoses. To investigate whether TRPS III is caused by TRPS1 mutations and to establish a genotype-phenotype correlation in TRPS, we performed extensive mutation analysis and evaluated the height and degree of brachydactyly in patients with TRPS I or TRPS III. We found 35 different mutations in 44 of 51 unrelated patients. The detection rate (86%) indicates that TRPS1 is the major locus for TRPS I and TRPS III. We did not find any mutation in the parents of sporadic patients or in apparently healthy relatives of familial patients, indicating complete penetrance of TRPS1 mutations. Evaluation of skeletal abnormalities of patients with TRPS1 mutations revealed a wide clinical spectrum. The phenotype was variable in unrelated, age- and sex-matched patients with identical mutations, as well as in families. Four of the five missense mutations alter the GATA DNA-binding zinc finger, and six of the seven unrelated patients with these mutations may be classified as having TRPS III. Our data indicate that TRPS III is at the severe end of the TRPS spectrum and that it is most often caused by a specific class of mutations in the TRPS1 gene.

TSPY, the 'testis-specific protein, Y-encoded', is the product of a tandem gene cluster on human proximal Yp. In order to gain insight into the function of this locus, we have analysed (I) the diversity of RNAs transcribed from the cluster, (II) the sequence homology of the deduced TSPY to other proteins, and (iii) its protein properties both in tissue extracts and in tissue sections, using a TSPY-specific antiserum. We have identified a set of distinct TSPY transcripts with diverse exon compositions. We show that TSPY has homology with other human and non-human proteins, including SET and NAP, factors that are suggested to play a role in DNA replication. Protein analysis revealed TSPY to occur mainly in a modified, putatively phosphorylated form. By immunostaining it was detected in distinct subsets of spermatogonia. TSPY was also strongly immunostained in early testicular carcinoma in situ (CIS), while seminomatous tumour cells stained less intensely. The spermatogonial cells of two XY-TFM-females gave a strong immune response. The data presented here point to a phosphorylation-dependent TSPY-function in early spermatogenesis, immediately prior to the spermatogonia-to-spermatocyte transition, and in early testicular tumorigenesis.