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Among full autosomal trisomies, only trisomies of chromosome 21 (Down syndrome), 18 (Edwards syndrome) and 13 (Patau syndrome) are compatible with postnatal survival. But the mechanisms, how a supernumerary chromosome disrupts the normal development and causes specific phenotypes, are still not fully explained. As an alternative to gene dosage effect due to the trisomic chromosome a genome-wide transcriptional dysregulation has been postulated. The aim of this study was to define the transcriptional changes in trisomy 13, 18, and 21 during early fetal development in order to obtain more insights into the molecular etiopathology of aneuploidy. Using oligonucleotide microarrays, we analyzed whole genome expression profiles in cultured amniocytes (AC) and chorionic villus cells (CV) from pregnancies with a normal karyotype and with trisomies of human chromosomes 13, 18 and 21. We observed a low to moderate up-regulation for a subset of genes of the trisomic chromosomes. Transcriptional levels of most of the genes on the supernumerary chromosome appeared similar to the respective chromosomal pair in normal karyotypes. A subset of chromosome 21 genes including the DSCR1 gene involved in fetal heart development was consistently up-regulated in different prenatal tissues (AC, CV) of trisomy 21 fetuses whereas only minor changes were found for genes of all other chromosomes. In contrast, in trisomy 18 vigorous downstream transcriptional changes were found. Global transcriptome analysis for autosomal trisomies 13, 18, and 21 supported a combination of the two major hypotheses. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We report on a 2-year-old girl with situs ambiguus comprising right-sided stomach and spleen, left-sided liver and complex cardiac defect. Psychomotor development of this patient was normal, and no other major abnormalities were present. Chromosome analysis revealed a de novo balanced chromosome translocation t(X;1)(q26;p13.1). Molecular cytogenetic investigations identified a breakpoint spanning BAC clone on the X-chromosome containing the ZIC3 gene. Mutations in ZIC3 are associated with situs ambiguus and cardiac defects predominantly in males. This is the first report of a live born girl with an X-autosome translocation involving the ZIC3 region.

Hyperimmunoglobulinemia D with periodic fever syndrome (HIDS) is a recessively inherited recurrent fever syndrome. We describe a family of 2 monozygotic twins and their mother with characteristic symptoms of HIDS, but normal levels of IgD and IgA, and with a dominant inheritance pattern. Mevalonate kinase (MK) activity was deficient in both children, and analysis of the MVK gene revealed compound heterozygosity for 2 new mutations, G25G and R277H. Being positioned adjacent to a donor splice site, the G25G mutation was shown by reverse transcription-polymerase chain reaction analyses to cause aberrant splicing of the MVK messenger RNA, thus being disease-relevant. The mother, who was also symptomatic during her childhood and adolescence, was a compound heterozygote for I268T and R277H. Our findings expand the genetic and ethnic spectrum of HIDS and show that the possible presence of this disease cannot be excluded based solely on inheritance patterns. In each case in which HIDS is clinically suspected, analysis of MK activity and/or the MVK gene (especially exons 9 and 11) should be performed.

We report on the spectrum and frequency of mutations in the phenylalanine hydroxylase (PAH) gene in 226 German families with PAH deficiency, most of them from Southern Germany. A total of 88 mutations were identified in 428 out of 438 mutant PAH alleles including one novel stop mutation L293X (c.878T>A). In three families, two phenylketonuria (PKU) mutations were found in cis, and in one family a de novo mutation was observed. A comparison of the results from Southern Germany with those of other parts of Western Germany showed no obvious local mutation clustering. In addition we studied the genotypic spectrum of 39 Turkish families with PAH deficiency. Twenty-three mutations were identified in 73 out of 75 Turkish chromosomes including two novel mutations: E280A (c.839A>G) in Exon 7 and IVS10-7C>A (c.1066-7C>A) in Intron 10. A new polymorphism IVS4+47C/T (c.441+47C>T) was found in mutant and normal PAH alleles. Screening of 170 German and 150 Turkish individuals without family history of PAH deficiency revealed 10 and 12 heterozygotes, respectively, a higher frequency of carriers than expected. A novel mutations of uncertain functional relevance, R169H (c.506G>A) in Exon 5 was found in two Turkish heterozygotes. Most of the Turkish heterozygotes carried mild mutations, indicating that mild forms of PAH deficiency may be more common in that population than previously recognised., (Copyright 2003 Wiley-Liss, Inc.)

Applying fluorescence in-situ hybridization (FISH) of various Y chromosomal DNA probes to four familial cases of human Yqs, it was possible to demonstrate that the formation of Yqs must have arisen from a reciprocal translocation involving the short arm of an acrocentric autosome and the heterochromatin of the long arm of the Y chromosome (Yqh). Breakpoints map within Yqh and the proximal short arm of an acrocentric autosome resulting in the gain of a nucleolus organizer region (NOR) including the telomere repeat (TTAGGG)n combined with the loss of the pseudoautosomal region 2 (PAR2) at the long arm of the recipient Y chromosome. In no case could the reciprocal product of an acrocentric autosome with loss of the NOR and gain of PAR2 be detected. Using the 15p-specific classical satellite-III probe D15Z1 in two of the four Yqs probands presented here, it could be shown that the satellited material originated from the short arm of chromosome 15. In contrast to the loss of PAR2 in Yqs chromosomes, another Y chromosomal variant (Yqh-) showing deletion of long-arm heterochromatin in Yq12 has retained PAR2 referring to an interstitial deletion of Yq heterochromatin in such deleted Y chromosomes.

Large deletions in Xq21 often are associated with contiguous gene syndromes consisting of X-linked deafness type 3 (DFN3), mental retardation (MRX), and choroideremia (CHM). The identification of deletions associated with classic CHM or DFN3 facilitated the positional cloning of the underlying genes, REP-1 and POU3F4, respectively, and enabled the positioning of the MRX gene in between these genes. Here, we report the cloning and characterization of a novel gene, ribosomal S6-kinase 4 (RSK4; HGMW-approved symbol RPS6KA6), which maps in the MRX critical region. RSK4 is completely deleted in eight patients with the contiguous gene syndrome including MRX, partially deleted in a patient with DFN3 and present in patients with an Xq21 deletion and normal intellectual abilities. RSK4 is most abundantly expressed in brain and kidney. The predicted protein of 746 amino acids shows a high level of homology to three previously isolated members of the human RSK family. RSK2 is involved in Coffin-Lowry syndrome and nonspecific MRX. The localization of RSK4 in the interval that is commonly deleted in mentally retarded males together with the high degree of amino acid identity with RSK2 suggests that RSK4 plays a role in normal neuronal development. Further mutation analyses in males with X-linked mental retardation must prove that RSK4 is indeed a novel MRX gene., (Copyright 1999 Academic Press.)

Small mutations in the POU domain gene POU3F4 were recently shown to cause X-linked deafness type 3 (DFN3) in nine unrelated males. The POU3F4 gene was found to be located outside four of five deletions associated with DFN3. Two of these deletions were situated more than 400 kb proximal to POU3F4. Employing PCR analysis of sequence tagged sites from this region we initially identified novel deletions in two DFN3 patients. To investigate this chromosomal segment in more detail, we extended a previously established 850 kb cosmid contig in the centromeric direction to a total size of 1500 kb. Cosmids from this contig were hybridized to DNA of 11 unrelated males with DFN3. In two patients, we identified deletions encompassing the POU3F4 gene and variably sized segments of Xq21.1. In six of the nine remaining patients which lacked mutations in the POU3F4 gene, smaller deletions were identified which, with one exception, overlap in a 8 kb segment 900 kb proximal to the POU3F4 gene. In one patient, we identified several small deletions in the vicinity of the 8 kb DNA segment. Together, deletions account for 56% (13/23) of all known DFN3 mutations, most (10/13) of which do not encompass the POU3F4 gene. The combined molecular data suggest that the deletion hot spot region in Xq21.1 contains another DFN3 gene or, alternatively, a sequence element involved in transcriptional regulation of POU3F4.

This is a case report on a 19-year-old patient with the chromosome constellation 48, XYYY. The patient showed signs of dysmorphism, mental retardation and problems in psychosocial functioning. A literature review revealed that individuals with this karyotype have widely varying phenotypes with regard not only to physical signs but also to brain functions and cognitive performance.

Gaucher's disease type I was diagnosed prenatally in one case. Using radiomarked natural lipid substrate the enzyme defect was demonstrated in amniotic cells cultured after amniocentesis in the 16th week of pregnancy. Rest activity of cerebroside beta-glucosidase was around 6% of control activity. After termination of pregnancy in the 19th week the diagnosis was confirmed in the fetus by demonstration of lack of enzyme activity in fetal fibroblasts and liver tissue. Enzyme levels of cerebroside beta-glucosidase in blood leucocytes of the couple who decided on termination of the pathological pregnancy were found compatible with but no proving the heterozygote state of Gaucher's disease. In the future the enzyme defect of affected probands should be determined early and as precisely as possible.

Levels of 17 alpha-hydroxyprogesterone were estimated by radioimmunoassay in 174 amniotic fluid specimens obtained from 162 normal pregnancies of 16-20 weeks gestation. Another 18 specimens from 11 normal pregnancies between 25-42 weeks gestation and 7 specimens from 7 women who each previously had given birth to a child affected with CAH were also studied. There was no sex difference in AF 17 alpha-OH-progesterone levels, nor any significant downward trend in concentrations throughout the observed gestation period. Among the 7 subjects with previous history of CAH offsprings, 4 demonstrated normal levels of AF 17 alpha-OH-progesterone and 3 significantly higher values. HLA-typing of the cultivated amniotic cells confirmed these 4 cases to be heterozygous for 21-hydroxylase deficiency. The three subjects with high AF 17 alpha-OH-progesterone levels delivered babies affected with CAH, although HLA-typing in one case was non-conclusive. The failure of HLA-typing in 1 case for a confirmatory diagnosis indicates that the prenatal diagnosis of CAH must continue to rest on joint endocrinological and genetical investigations.