Reciprocal chromosome translocations involving short arm of chromosome 9 as a risk factor of unfavorable pregnancy outcomes after meiotic malsegregation 2:2.

PURPOSE: Genetic counseling of carriers with individual chromosome translocation requires information on how balanced reciprocal chromosome translocations (RCT) will segregate, what possible form of unbalanced embryo/fetus/child can occur, and the survival rates that have been observed in the particular families. We collected new empirical data and evaluated pedigrees of RCT carriers involving 9p in order to improve risk figures. MATERIAL AND METHODS: Empirical data on 241 pregnancies of 70 carriers were collected from 32 pedigrees of carriers of RCT at risk for a single 9p segment imbalance (RCT9p) from the literature and unpublished data. The probability rates of particular types of pathology have been calculated according to the method of Stengel-Rutkowski and Stene. Cytogenetic interpretation was based on GTG, RBG and FISH techniques. RESULTS: The probability rate for unbalanced offspring at birth for the whole group of pedigrees was calculated as 17.8+/-3% (33/185) (high risk). Considering the size of the imbalanced segment of 9p, the probability rates for RCT carriers with a breakpoint position at 9p22 at 9p13 and at 9p11.2 were estimated separately, and were found as 21.2+/-4.4% (18/85), 25+/-8.8% (6/24) and 11.8+/-3.7% (9/76), respectively. For unbalanced fetuses at 2nd prenatal diagnosis, we found the risk value as 57.9+/-11.3 % (11/19). The risk value for unkaryotyped stillbirths/early deaths of newborns and miscarriages were 5.4+/-1.7% (10/185) (medium risk) and 13+/-2.8% (rate 24/185) (high risk) respectively. CONCLUSIONS: Our results showed that the recurrence probability rates are different for particular categories of unfavorable pregnancy outcomes. How much they are dependent on the size of 9p chromosome segments taking part in the imbalance needs further studies based on a larger number of observations.

Further delineation of Pitt-Hopkins syndrome: phenotypic and genotypic description of 16 novel patients.

BACKGROUND: Haploinsufficiency of the gene encoding for transcription factor 4 (TCF4) was recently identified as the underlying cause of Pitt-Hopkins syndrome (PTHS), an underdiagnosed mental-retardation syndrome characterised by a distinct facial gestalt, breathing anomalies and severe mental retardation. METHODS: TCF4 mutational analysis was performed in 117 patients with PTHS-like features. RESULTS: In total, 16 novel mutations were identified. All of these proven patients were severely mentally retarded and showed a distinct facial gestalt. In addition, 56% had breathing anomalies, 56% had microcephaly, 38% had seizures and 44% had MRI anomalies. CONCLUSION: This study provides further evidence of the mutational and clinical spectrum of PTHS and confirms its important role in the differential diagnosis of severe mental retardation.

Translocation form of Wolf-Hirschhorn syndrome --assessment of recurrence rate probability.

PURPOSE: The families experienced by occurrence of child with Wolf-Hirschhorn syndrome (WHS: OMIM # 194190) and by other unfavourable pregnancy outcomes (miscarriages or stillbirths/early deaths and partial trisomy 4p imbalance leading to intellectual disability in live born progeny) are asking for genetic counseling. In order to obtain the recurrence probability rates for the particular forms of unfavourable pregnancy we collected the empirical data and evaluated pedigrees of reciprocal chromosome translocations (RCT) carriers involving 4p. Results were applied to family of carrier of t(4;11)(p16.1;q23.3) ascertained by four miscarriages, in which latter the girl with WHS was born. MATERIAL AND METHODS: Total empirical data about 170 pregnancies of 46 carriers were collected from 25 pedigrees RCT at risk for single segment imbalance. Classification was based mostly on cytogenetic methods. The probability rates of particular type of pathology related to total number of pregnancies after ascertainment correction have been calculated according to the method of Stengel-Rutkowski and Stene. RESULTS: The risk figures for unbalanced offspring after 2:2 disjunction and adjacent-1 segregation for whole group of pedigrees were calculated as 15.2 +/- 3.5% (16/105), for unbalanced fetuses at second trimester of prenatal diagnosis as 50 +/- 13.4% (7/14), for miscarriages about 19 +/- 3.8% (20/105) and for stillbirths/early death as 15.2 +/- 3.5% (16/105). The higher probability rate for RCT carriers at risk for distal 4p--shorter segment imbalance (28.6 +/- 12%, 4/14) in comparison to the rate for proximal (medium) one as 15.4 +/- 4.5% (10/65) and to more proximal (longer) one as 7.7 +/- 5.2% (2/26) were found. CONCLUSIONS: Our results confirm that the recurrence probability rates are different for particular categories of unfavourable pregnancy outcomes and dependent on size and genetic content of unbalanced 4p segments.

Partial trisomy of long arm of chromosome 4 as a result of dir dup (4)(q27q31.3) de novo.

The phenotype of a girl at age of 12 years with a partial trisomy 4q caused by unique direct duplication 4q27 --> q31.3 included the thick, broad and straight eyebrows, upward slanting palpebral fissures, a deep-set eyes, narrow bridge and long back of the nose, flattened philtrum columns, narrow of vermilion borders of both upper and lower lips, protrusion of maxillary alveolar processus and anterior teeth together with shortened and posteriorly situated mandible, malocclusion corresponding with II class of Angle and long fingers, narrowing towards distal phalanges has been described. Further investigations are needed to delineate the clinical spectrum of features essential for partial trisomy 4q.

A natural history of a child with monosomy 5p syndrome (Cat-cry/Cri-du-chat syndrome) during the 18 years of follow-up.

A record of a natural history of a long-term case study devoted to monosomy 5p (Cat-cry/Cri-du-chat) syndrome has been described rarely. Knowledge on the range of the changes in phenotype attributable to advancing age can be useful in clinical diagnosis of monosomy 5p at the different developmental stages, including adolescence, as well in prognosis for genetic counseling. In this case a detailed analysis of the morphologic phenotype in a girl with del(5)(p13.3) observed from 4 months to 18 years of age is reported. The comparative analysis of the girl's phenotype in different developmental stages has revealed that microcephaly, flat occipital region, face asymmetry, wide spaced palpebral fissures, epicanthic folds, small mouth fissure, thin mucous lip, small and low set ears and short IV metacarpals has not changed with advancing age. However, facial asymmetry was more evident, frontal tubers were less prominent, nasal root and back became prominent nasal back became elongated, the subnasal region was shorter and marked malocclusion appeared.

Physical and developmental phenotype analyses in a boy with Wolf-Hirschhorn syndrome.

Wolf-Hirschhorn syndrome (WHS) is a rare genetic condition with characteristic facial traits, organ malformations, functional impairment and developmental delay due to partial short arm monosomy of chromosome 4. Although several hundreds of cases have been published to date, a systematic collection of its clinical symptoms and anthropological traits is missing in the literature, and reports on abilities and needs of children with WHS are scanty. Results of detailed physical and developmental phenotype analyses in a 1 10/12-year-old boy with monosomy 4p15.2-pter are presented. Physical analyses were based on systematic data acquisition. They disclosed a total of 32 clinical symptoms and 46 anthropological traits. Developmental analyses were based on the child's interactive play in an environment structured according to Montessori principles. They disclosed a total of 44 abilities and a number of needs to be satisfied by the environment for the support of the child's psychic and intellectual growth. While the physical phenotype is important for the diagnostic process, the developmental phenotype is essential for parental counseling.

Genetic counseling in carriers of reciprocal chromosomal translocations involving long arm of chromosome 16.

Families with balanced chromosomal changes ascertained by unbalanced progeny, miscarriages, or by chance are interested in their probability for unbalanced offspring and other unfavorable pregnancy outcomes. This is usually done based on the original data published by Stengel-Rutkowski et al. several decades ago. That data set has never been updated. It is particularly true for the subgroup with low number of observations, to which belong reciprocal chromosomal translocations (RCTs) with breakpoint in an interstitial segment of 16q. The 11 pedigrees from original data together with the new 18 pedigrees of RCT carriers at risk of single-segment imbalance detected among 100 pedigrees of RCT carriers with breakpoint position at 16q were used for re-evaluation of the probability estimation for unbalanced offspring at birth and at second trimester of prenatal diagnosis, published in 1988. The new probability rate for unbalanced offspring after 2 : 2 disjunction and adjacent-1 segregation for the total group of pedigrees was 4 +/- 3.9% (1/25). In addition, the probability estimate for unbalanced fetuses at second trimester of prenatal diagnosis was calculated as 2/11, i.e. 18.2 +/- 11.6%. The probability rates for miscarriages and stillbirths/early deaths were about 16 +/- 7.3% (4/25) and <2% (0/25), respectively. Considering different segment lengths of 16q, higher probability rate (0/8, i.e. <6.1%) for maternal RCT carriers at risk of distal 16q segment imbalance (shorter segment) was obtained in comparison with the rate (0/10, i.e. <4.8%) for RCT at risk of proximal segment imbalance (longer segment). It supports findings obtained from the original data for RCT with other chromosomes, where the probability for unbalanced offspring generally increased with decreasing length of the segments involved in RCT. Our results were applied for five new families with RCT involving 16q, namely three at risk of single-segment imbalance [t(8;16)(q24.3;q22)GTG, ish(wcp8+,wcp16+;wcp8-,wcp16+), t(11;16)(q25;q22)GTG, and t(11;16)(q25;q13)GTG] and two with RCT at risk of double-segment imbalance [t(16;19)(q13;q13.3)GTG, isht(16;19)(q13;q13.3) (D16Z3+,16QTEL013-D19S238E+,TEL19pR-; D16Z3-, D19S238E-,TEL19pR+), and t(16;20)(q11.1;q12)GTG, m ish,t(16;20)(wcp16+,wcp20+;wcp16+,wcp20+)]. They have been presented in details to illustrate how the available empiric data could be used in practice for genetic counseling.

Sequence polymorphisms of the EDA and the DL genes in the patients with an X-linked and an autosomal forms of anhidrotic ectodermal dysplasia.

Oligodontia, sparse hair and deficiency of eccrine sweat glands are the features characteristic for the phenotype of the patients with anhidrotic ectodermal dysplasia (EDA). This syndrome is caused by mutations in the EDA or DL (downless) genes, encoding members of the TNF ligand and TNF receptor families, involved in the communication between the cells during embryonic life. We investigated both the coding and noncoding regions of the EDA and the DL genes in the patients exhibiting clinical symptoms of ectodermal dysplasia. Sequence analysis of the amplified fragments of the EDA gene revealed polymorphisms in introns three, four and five. The polymorphism in intron four was found in about 60% of the patients and was no more frequent than in the normal individuals. The two other polymorphisms were rare. Polymorphisms were also observed in exons 9 and 12 of the DL gene, but they did not alter the sequence of the protein product of the gene. Our results indicate that in order to accelerate screening for the mutations of the EDA gene and reduce the costs, the amplified fragments should not contain intronic sequences. However, in the case of the DL gene, where polymorphic sites are located in exons, restriction analysis with the use of appropriate enzyme should be conducted, but usually sequencing analysis could not be avoided.

Construction of a detailed physical and transcript map of the candidate region for Russell-Silver syndrome on chromosome 17q23-q24.

Russell-Silver syndrome (RSS) is a heterogeneous disorder characterized mainly by pre- and postnatal growth retardation and characteristic dysmorphic features. The genetic cause of this syndrome is unknown. However, two autosomal translocations involving chromosome 17q25 were reported in association with RSS. Molecular analysis of the breakpoint on chromosome 17 of the de novo translocation previously described as t(1;17)(q31;q25) enabled us to refine the localization of the chromosome 17 breakpoint to 17q23-q24. Since no detailed mapping data were available for this region, we established a contig of yeast artificial chromosomes, P1 artificial chromosomes, bacterial artificial chromosomes, and cosmid clones for a 17q segment flanked by the sequence-tagged site (STS) markers D17S1557 and D17S940. This contig covers a physical distance of 4-5 Mb encompassing several novel markers. A transcript map was constructed by assigning genes and expressed sequence tags to the clone contig, and altogether 74 STS markers were mapped. Furthermore, the locus order and content provide insight into several duplication events that have occurred in the chromosomal region 17q23-q24. On the basis of our refined map, we have reduced the translocation breakpoint region to 65 kb between the newly derived markers 58T7 and CF20b. These data provide the molecular tools for the final identification of the RSS gene in 17q23-q24.

Genotypic and phenotypic spectrum in tricho-rhino-phalangeal syndrome types I and III.

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.

[Genetic risk of families with t(1;2)(q42;q33) GTG, RHG, QFQ, FISH]. / Ryzyko genetyczne rodzin obciazonych translokacja chromosomowa t(1;2)(q42;q33) GTG, RHG, QFQ, FISH.

OBJECTIVES: A central concept in genetic counseling is the estimation of the probability of recurrence of unfavourable pregnancy outcomes (abortion, stillbirth and birth at malformed child). In case of chromosomal changes estimates are made on basis of segregation analyses in actual pedigree. If we have a few of pedigree members than risk estimate should be performed on basis combined our data and empiric data from literature. We present individual genetic risk for carriers of unique reciprocal translocation t(1;2)(q42;q33) detected through karyotyping of the patient with miscarriage. MATERIAL AND METHODS: The pedigree consisted 5 families of t(1;2)(q42;q33) carriers with 15 members of progeny was evaluated according to Stene and Stengel-Rutkowski. Cytogenetic analysis of persons of these families (7 persons) was performed on blood samples using GTG, RHG, QFQ and FISH techniques. Additional RCT pedigree analysis of Stengel-Rutkowski et at Collection, Polish Collection, Lituanian Collection, Bielorussian Collection and an available literature cases were performed. RESULTS: The translocation was classified as translocation at risk for double segment imbalances for trisomy 1q42-->qter together with monosomy 2q33-->qter or monosomy 1q42-->qter together with trisomy 2q33-->qter after 2:2 disjunction after adjacent-1 segregation of the meiotic chromosomes. Two improved risk values for RCT with segments 1q42-->qter, 2q33-->qter were obtained i.e. 6/44 (13.6% +/- 5.2%) and 4/20 (20% +/- 8.9%). The probability of occurrence for this translocation carriers was estimated as 7% (medium risk). On basis of direct analysis at presented pedigree a risk for miscarriage was estimated as 2/9. CONCLUSIONS: 1. Carrierships of t(1;2)(q42;q33) increased population risk value for unbalanced progeny at birth by 7% (medium risk) and for miscarriage 2/9. 2. Causative relation between presence of t(1;2)(q42;q33) and miscarriages is suggested. 3. Updated, new genetic risk values for RCT at risk for single segment 1q42-->qter imbalance is 6/44 (13.6% +/- 5.2%) at birth and for single segment 2q33-->qter imbalance is 4/20 (20% +/- 8.9%).

[Turner syndrome in a girl with marker chromosome in karyotype]. / Zespól Turnera u dziewczynki z chromosomem markerowym w kariotypie.

OBJECTIVES: There are suggestion, that Turner syndrome (TS) patients with mosaic karyotype for a Y-DNA-containing cell line are at risk of Y-induced gonadoblastoma. The TS patients in whom some or all cells contain a marker chromosome of unknown origin and those in whom there is clitoromegaly or other evident virillisation should be tested by FISH or PCR techniques. DESIGN: The aim of our study to present a TS girl with mosaic karyotype and marker chromosome, which origin from X chromosome was detected by FISH method. MATERIAL AND METHODS: 5-years old girl in whom TS was established. Clinical analysis included the full dysmorphic and clinical phenotype of TS. Chromosome analysis was performed on peripheral blood samples using routine cytogenetic methods and FISH technique. RESULTS: Clinical examination of girl showed many typical signs of TS besides of normal weight and length at birth and not typical for TS patients heart defect. First routine chromosome analysis, at age of 6 month, showed only 45,X cell line, Second study revealed mosaic karyotype with marker chromosome. FISH analysis for interphase nuclei and metaphase chromosomes using X centromere probe explained origin of marker from X chromosome. The karyotype was 45,X[155]/46,X,+mar[8].fish mar(X)(DXZ1+). CONCLUSION: Presence of marker chromosome in karyotype of patient with TS may modify their phenotype and it is a indication for molecular examination by FISH technique.

[Evaluation of some clinical parameters in patients with retinitis pigmentosa in relationship to the type of inheritance]. / Ocena wybranych parametrów klinicznych u pacjentów z retinitis pigmentosa z uwzglednieniem sposobu dziedziczenia choroby.

PURPOSE: Analysis of selected clinical parameters in patients with various types of retinitis pigmentosa. PATIENTS AND METHODS: We examined 51 patients aged 8-67 suffering from different genetic forms of RP identified on the ground of pedigree analysis. We analyzed onset of nyctalopia, degree of retinal degeneration, degree of visual field loss, dark adapted electroretinographic testing flicker (ERG) and presence of posterior subcapsular cataract. CONCLUSIONS: XLRP is one of the most severe RP forms. In the groups with ADRP and sRP, the patients have varied expression of disease.

Immortalization and characterization of Nijmegen Breakage syndrome fibroblasts.

Nijmegen Breakage Syndrome (NBS) is a very rare autosomal recessive chromosomal instability disorder characterized by microcephaly, growth retardation, immunodeficiency and a high incidence of malignancies. Cells from NBS patients are hypersensitive to ionizing radiation (IR) and display radioresistant DNA synthesis (RDS). NBS is caused by mutations in the NBS1 gene on chromosome 8q21 encoding a protein called nibrin. This protein is a component of the hMre11/hRad50 protein complex, suggesting a defect in DNA double-strand break (DSB) repair and/or cell cycle checkpoint function in NBS cells. We established SV40 transformed, immortal NBS fibroblasts, from primary cells derived from a Polish patient, carrying the common founder mutation 657del5. Immortalized NBS cells, like primary cells, are X-ray sensitive (2-fold) and display RDS following IR. They show an increased sensitivity to bleomycin (3.5-fold), etoposide (2.5-fold), camptothecin (3-fold) and mitomycin C (1.5-fold), but normal sensitivity towards UV-C. Despite the clear hypersensitivity towards DSB-inducing agents, the overall rates of DSB-rejoining in NBS cells as measured by pulsed field gel electrophoresis were found to be very similar to those of wild type cells. This indicates that the X-ray sensitivity of NBS cells is not directly caused by an overt defect in DSB repair.

Distortion products otoacoustic emissions in diagnosis of hearing loss in Down syndrome.

This study was carried out to investigate the features of hearing impairment in subjects with Down syndrome. Forty-seven children and 14 adults with Down syndrome were included in the study. In all cases, a complete otorhinolaryngological examination was performed, followed by audiological assessment. Depending on age, intellectual level and middle ear status the following examinations were performed: pure-tone 'play audiometry', tympanometry, acoustic reflex, auditory brain response (ABR) and distortion products otoacoustic emissions (DPOAE). The results were compared with age matched control groups. Among the group of children with Down syndrome, we have frequently found impairment of the conductive function of the middle ear which was expressed by pathological tympanometry. Tympanometry of B and C type was detected in 56% of ears. The amplitude of DPOAE was lower in children with Down syndrome than in the control group. This difference was more expressed in adults with Down syndrome. DPOAE examination results in subjects with Down syndrome without conductive hearing loss indicate early age related inner ear impairment.

Three novel SRY mutations in XY gonadal dysgenesis and the enigma of XY gonadal dysgenesis cases without SRY mutations.

Mutations in the Y-located testis-determining gene SRY are one cause for XY sex reversal. We have previously identified four SRY mutations in a total of 45 sex-reversed females with XY gonadal dysgenesis (XY GD). In a new sample of 16 XY GD cases, three previously undescribed SRY mutations were identified. Two are point mutations that lead to amino acid substitutions in the HMG domain of SRY, M64R, and F67V. The third SRY mutation is a single base insertion 5' to the HMG box within codon 43, converting this lysine codon to a stop codon (K43X). A total of 33 SRY mutations have so far been described that account for only 10-15% of XY GD females. A further 10-15% of these cases result from deletion of SRY due to aberrant X/Y interchange. The etiology of the remaining 70-80% of XY GD cases is still enigmatic. Possible explanations for these XY sex-reversal cases are discussed.

[Ultrasound diagnosis of four fetuses with Fraser syndrome during pregnancy]. / Ocena ultrasonograficzna czterech plodów z zespolem Frasera w okresie ciazy.

The authors present results of sonography analysis of four fetuses with Fraser syndrome. First woman had prenatal diagnosis by ultrasounds and ascites of fetus with polyhydramnion were diagnosed in two of her successive pregnancies. The second pregnant woman was observed by ultrasound and lack of kidney was detected. The third pregnant one was diagnosed at first trimester of pregnancy and results of sonography examination were at norm. After delivery, Fraser syndrome in all of these children was diagnosed. Findings on sonography included: ascites of fetus, polyhydramnion, hydrocephalus and nonvisualization of kidney. Sonography is more efficient in the diagnosis of Fraser syndrome in a fetus whose parents had had a previous affected child because of diverse anomalies were observed.

[Familial complex chromosome translocation of t(1;4;10)(q21.3;q27;q26.1) verified by FISH]. / Rodzinne wystepowanie zlozonej translokacji chromosomowej t (1;4;10) (q21.3;q27;q26.1) zweryfikowanej metoda FISH.

The inheritance complex chromosome translocation is a rare. A familial complex chromosome rearrangement t(1;4;10)(q21.3;q27;q26.1) involving three chromosomes ascertained due to four spontaneous abortions in phenotypically normal childless woman there is presented. Cytogenetic analysis according to classic banding techniques were verified by fluorescent in situ hybridization (FISH) technique.

[Pedigree analysis of childless families of reciprocal chromosome translocation carriers]. / Analiza rodowodowa bezdzietnych rodzin obciazonych nosicielstwem translokacji chromosomowych wzajemnych.

OBJECTIVES: Pedigree analysis of childless families of unique reciprocal chromosome translocation (RCT) carriers may be useful for clinical prognosis and genetic counselling. MATERIAL AND METHODS: The group 13 childless families of RCT carriers were detected. Cytogenetic analysis of RCT was performed on blood samples using GTG and RBG banding technique. RESULTS: Thirteen pedigrees were constructed on basis of 64 cytogenetic results and anamnestic data of 62 spontaneous abortions and 7 stillbirths. Familial RCT were found in ten families. In addition fourteen relatives of the RCT carriers have had healthy children. Further observations showed other three healthy children among progeny of eight families. Low risk for unbalanced progeny at birth were estimate in most families. CONCLUSION: Childless families of RCT carriers have possibility to have healthy offsprings. Spontaneous abortions are result of RCT carrierstrip.