One novel and two recurrent missense DKC1 mutations in patients with dyskeratosis congenita (DKC).

X-linked dyskeratosis congenita (DKC) is a progressive multisystem disorder most severely affecting tissues with a high cellular turnover such as skin, mucous membranes, and blood. Most patients die of bone marrow failure, although the chances of succumbing to various types of cancer and pulmonary disease are also high. DKC is caused predominantly by missense mutations in the DKC1 gene linked to Xq28. Some of the clinical features are reminiscent of premature ageing and this agrees with recent indications that DKC could be a telomere maintenance disorder. There is considerable variability in the type, severity, and age at onset of the various anomalies. Recognition of this has increased with the finding that patients with Hoyeraal-Hreidarsson syndrome (HHS) who exhibit severe neurological problems in addition to early-onset pancytopenia, also bear mutations in the DKC1 gene. For these reasons, and compounded by the range of mutations, phenotype-genotype correlations and accurate assessments of prognosis have not been possible. To complement the present data, we here report on three new cases of DKC and their mutations. One is a novel mutation in the exon 3 (K43E). The other two represent a frequently recurring mutation in exon 11 (A353V) and a less frequently recurring mutation in the exon 3 (T49M).

p63 Gene mutations in eec syndrome, limb-mammary syndrome, and isolated split hand-split foot malformation suggest a genotype-phenotype correlation.

p63 mutations have been associated with EEC syndrome (ectrodactyly, ectodermal dysplasia, and cleft lip/palate), as well as with nonsyndromic split hand-split foot malformation (SHFM). We performed p63 mutation analysis in a sample of 43 individuals and families affected with EEC syndrome, in 35 individuals affected with SHFM, and in three families with the EEC-like condition limb-mammary syndrome (LMS), which is characterized by ectrodactyly, cleft palate, and mammary-gland abnormalities. The results differed for these three conditions. p63 gene mutations were detected in almost all (40/43) individuals affected with EEC syndrome. Apart from a frameshift mutation in exon 13, all other EEC mutations were missense, predominantly involving codons 204, 227, 279, 280, and 304. In contrast, p63 mutations were detected in only a small proportion (4/35) of patients with isolated SHFM. p63 mutations in SHFM included three novel mutations: a missense mutation (K193E), a nonsense mutation (Q634X), and a mutation in the 3' splice site for exon 5. The fourth SHFM mutation (R280H) in this series was also found in a patient with classical EEC syndrome, suggesting partial overlap between the EEC and SHFM mutational spectra. The original family with LMS (van Bokhoven et al. 1999) had no detectable p63 mutation, although it clearly localizes to the p63 locus in 3q27. In two other small kindreds affected with LMS, frameshift mutations were detected in exons 13 and 14, respectively. The combined data show that p63 is the major gene for EEC syndrome, and that it makes a modest contribution to SHFM. There appears to be a genotype-phenotype correlation, in that there is a specific pattern of missense mutations in EEC syndrome that are not generally found in SHFM or LMS.

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.

Lenz-Majewski hyperostotic dwarfism: reexamination of the original patient.

In 1974, Lenz and Majewski gave a short description of a 2-year-old girl with generalized hyperostosis, proximal symphalangism, syndactyly, brachydactyly, cutis laxa, mental retardation, marked hypertelorism, and enamel hypoplasia. This disorder was later named Lenz-Majewski hyperostotic dwarfism. We describe the reexamination of the original patient at the age of 30 years.

Effect of the size of the deletion and clinical manifestation in Wolf-Hirschhorn syndrome: analysis of 13 patients with a de novo deletion.

We performed clinical, cytogenetic, and molecular analyses on 13 patients (8 females and 5 males, aged 6 months to 13 years) with Wolf-Hirschhorn syndrome due to de novo deletions of chromosome 4p. All patients presented with the typical facial gestalt, microcephaly, and profound mental retardation. Other clinical signs were low birth weight (10/13; 77%), postnatal short stature (8/12; 66%), muscular hypotonia (12/13; 92%), seizures (11/13; 85%), congenital heart defects (4/13; 31%), colobomata of iris (4/12; 33%), genital anomalies (4/13; 31%), deafness (3/13; 23%), and renal anomalies (3/13; 23%). The smallest deletion was a submicroscopic terminal deletion of nearly 2.5 Mb. The largest was a terminal deletion of nearly 30 Mb. Cleft lip/palate, preauricular pits/tags, and congenital heart defects were present only in patients with terminal deletions larger than 10 Mb. The deviations from mean birth weight, birth length, and postnatal head circumference correlated with the size of the deletion. Determining the parental origin of the deletion with microsatellite markers, the maternal allele was missing in three patients and the paternal allele in eight patients. Our observations support the existence of a partial genotype-phenotype correlation in Wolf-Hirschhorn syndrome.

Methylation mosaicism of 5'-(CGG)(n)-3' repeats in fragile X, premutation and normal individuals.

Fragile X syndrome (FRAXA) is characterized at the molecular level by an expansion of a naturally occurring 5'-(CGG)(n)-3' repeat in the promoter and 5'-untranslated region (5'-UTR) of the fragile X mental retardation (FMR1) gene on human chromosome Xq27.3. When expanded, this region is usually hypermethylated. Inactivation of the FMR1 promoter and absence of the FMR1 protein are the likely cause of the syndrome. By using the bisulfite protocol of the genomic sequencing method, we have determined the methylation patterns in this region on single chromosomes of healthy individuals and of selected premutation carriers and FRAXA patients. In control experiments with unmethylated or M- Sss I-premethylated DNAs, this protocol has been ascertained to reliably detect all cytidines or 5-methylcytidines as unmethylated or methylated nucleotides, respectively. Analyses of the DNA from FRAXA patients reveal considerable variability in the lengths of the 5'-(CGG)(n)-3' repeats and in the levels of methylation in the repeat and the 5'-UTR. In one patient (OEl) with high repeat length hetero-geneity ( n = 15 to >200), shorter repeats (n = 20-80) were methylated or unmethylated, longer repeats ( n = 100-150) were often completely methylated, but one repeat with n = 160 proved to be completely unmethylated. This type of methylation mosaicism was observed in several FRAXA patients. In healthy females, methylated 5'-CG-3' sequences were found in some repeats and 5'-UTRs, as expected for the sequences from one of the X chromosomes. The natural FMR1 promoter is methylation sensitive, as demonstrated by the loss of activity in transfection experiments using the unmethylated or M- Sss I-premethylated FMR1 promoter fused to the luciferase gene as an activity indicator.

[Retinitis pigmentosa, terminal renal insufficiency and Caroli syndrome: new associations with Opitz trigonocephaly syndrome]. / Retinitis pigmentosa, terminale Niereninsuffizienz und Caroli-Syndrom: neue Assoziationen zum Opitz-Trigonocephalie-Syndrom.

We report on a new patient with Opitz trigonocephaly syndrome. In addition to the findings typical of this mental retardation syndrome, the present patient has retinitis pigmentosa, Caroli's syndrome and renal failure, which is undergoing hemodialysis. This association is never observed before in patients with Opitz trigonocephaly syndrome. This case demonstrate, that with increased survival of patients with mental retardation syndromes, the phenotypes possible are modified.

FISH studies in 45 patients with Rubinstein-Taybi syndrome: deletions associated with polysplenia, hypoplastic left heart and death in infancy.

Rubinstein-Taybi syndrome (RTS) is a dominant Mendelian disorder characterised by mental retardation, a typical facies, broad thumbs and short stature. Previous reports indicated that 4-25% of RTS patients have a submicroscopic 16p13.3 deletion of the CBP gene. Using FISH and cosmid probes RT100, RT191 and RT203 we studied 45 RTS patients from Germany, the Czech Republic, Austria and Turkey and found four deletions (8.9%, pooled data including other studies: 11%). All deletions were interstitial; three spanned the CBP gene (RT100-RT203) and one was smaller (RT100 only). Previous studies reported no phenotype-genotype correlation between RTS patients with or without a deletion. Our findings suggest a more severe phenotype. The mean age at presentation was 0.96 years in patients with a deletion as against 11.12 years in those without. Patients A and B with a deletion died in infancy which is rare in RTS and was not observed among the other patients. Patients A and D had accessory spleens, Patient A with hypoplastic left heart, abnormal pulmonary lobulation and renal agenesis. This is the second report of hypoplastic left heart and the first report of polysplenia with RTS. The signs suggest a developmental field defect (disturbance of laterality) either as a newly recognised pattern of RTS, or alternatively a novel contiguous gene syndrome.

Mutation analysis of core binding factor A1 in patients with cleidocranial dysplasia.

Cleidocranial dysplasia (CCD) is a dominantly inherited disorder characterized by patent fontanelles, wide cranial sutures, hypoplasia of clavicles, short stature, supernumerary teeth, and other skeletal anomalies. We recently demonstrated that mutations in the transcription factor CBFA1, on chromosome 6p21, are associated with CCD. We have now analyzed the CBFA1 gene in 42 unrelated patients with CCD. In 18 patients, mutations were detected in the coding region of the CBFA1 gene, including 8 frameshift, 2 nonsense, and 9 missense mutations, as well as 2 novel polymorphisms. A cluster of missense mutations at arginine 225 (R225) identifies this residue as crucial for CBFA1 function. In vitro green fluorescent protein fusion studies show that R225 mutations interfere with nuclear accumulation of CBFA1 protein. There is no phenotypic difference between patients with deletions or frameshifts and those with other intragenic mutations, suggesting that CCD is generally caused by haploinsufficiency. However, we were able to extend the CCD phenotypic spectrum. A missense mutation identified in one family with supernumerary teeth and a radiologically normal skeleton indicates that mutations in CBFA1 can be associated exclusively with a dental phenotype. In addition, one patient with severe CCD and a frameshift mutation in codon 402 had osteoporosis leading to recurrent bone fractures and scoliosis, providing first evidence that CBFA1 may help maintain adult bone, in addition to its function in bone development.

Microcephalic osteodysplastic primordial dwarfism type II: report of three cases and review.

We report on three further patients with microcephalic osteodysplastic dwarfism type II. All children have marked intrauterine and postnatal growth failure, microcephaly, and mental and statomotor retardation. They are disproportionately short statured due to short limbs. Characteristic skeletal abnormalities are small iliac wings with flat acetabular angles, coxa vara, V-shaped distal femoral metaphyses, and triangular distal femoral epiphyses, as well as pseudoepiphyses of metacarpals, short first metacarpals, and brachymesophalangy V. At age 3 years, bilateral epiphyseolysis of the femoral heads occurred in case 1. Including our patients, 17 cases have been published so far. We review the clinical picture and the cause.

Partial trisomy 6p from a de novo translocation (6;18) with variable mosaicism in different tissues.

Partial trisomy 6p is regarded as a distinct phenotype with short stature, failure to thrive, facial dysmorphisms with blepharophimosis, mental retardation and other malformations. An 18-month-old girl with typical features of partial trisomy 6p showed a de novo unbalanced translocation resulting in partial trisomy 6p21 to pter and partial monosomy 18p11 to pter. The translocation was observed in all fibroblasts analyzed, but only in 6% of the peripheral lymphocytes.

Synpolydactyly phenotypes correlate with size of expansions in HOXD13 polyalanine tract.

Synpolydactyly (SPD) is a dominantly inherited congenital limb malformation. Typical cases have 3/4 finger and 4/5 toe syndactyly, with a duplicated digit in the syndactylous web, but incomplete penetrance and variable expressivity are common. The condition has recently been shown to be caused by expansions of an imperfect trinucleotide repeat sequence encoding a 15-residue polyalanine tract in HOXD13. We have studied 16 new and 4 previously published SPD families, with between 7 and 14 extra residues in the tract, to analyze the molecular basis for the observed variation in phenotype. Although there is no evidence of change in expansion size within families, even over six generations, there is a highly significant increase in the penetrance and severity of phenotype with increasing expansion size, affecting both hands (P = 0.012) and feet (P < 0. 00005). Affected individuals from a family with a 14-alanine expansion, the largest so far reported, all have a strikingly similar and unusually severe limb phenotype, involving the first digits and distal carpals. Affected males from this family also have hypospadias, not previously described in SPD, but consistent with HOXD13 expression in the developing genital tubercle. The remarkable correlation between phenotype and expansion size suggests that expansion of the tract leads to a specific gain of function in the mutant HOXD13 protein, and has interesting implications for the role of polyalanine tracts in the control of transcription.

Cardio-facio-cutaneous (CFC) syndrome--a distinct entity? Report of three patients demonstrating the diagnostic difficulties in delineation of CFC syndrome.

We report on three patients with probable cardio-facio-cutaneous (CFC) syndrome. They present clinical findings of this condition such as: growth failure, heart defects, typical craniofacial appearance, ectodermal abnormalities, and developmental delay. We also give a detailed review of the previously published articles on CFC syndrome and discuss the differences between CFC, Noonan, and Costello syndromes. Other differential diagnoses are considered.

Blepharo-cheilo-dontic (BCD) syndrome.

Patients with the autosomal dominant ble-pharo-cheilo-dontic (BCD) syndrome have ectropion of lower eyelids, distichiasis of upper eyelids, euryblepharon, bilaterally cleft lip/palate, oligodontia, and conical crown form. Initially known under the eponym "Elschnig syndrome" (1912), BCD syndrome has been described in binary, ternary, and quaternary combination. There is overlap with the syndrome reported by Martínez et al. [1987], postaxial acrofacial dysostosis (Miller syndrome, Genée-Wiedemann syndrome), and a syndrome reported briefly by Warburg.

Goldenhar, Möbius and hypoglossia-hypodactyly anomalies in a patient: syndrome or association?

UNLABELLED: The Möbius, Goldenhar and hypoglossia-hypodactyly anomalies are usually sporadic conditions with a recurrence risk of about 2%. The combination of Goldenhar and one or the two others is rare, whereas the concomitant occurrence of Möbius and hypoglossia-hypodactyly, and/or Poland, and/or Klippel-Feil anomaly is well known. Pathogenetically, vascular disruptions around the 4th embryonic week have been hypothesized. In vivo and pathological studies as well as animal models support this theory for all the above-mentioned combinations. Whether a preceding blastogenetic alteration is an influencing factor or a disorganization mutation, remains unclear. We describe a 3-year-old girl with bilateral anotia, epidermoid on the right eye, 6th and 7th nerve palsy, hypoglossia, left hypodactyly, and ventricular septal defect. CONCLUSION: We wish to emphasize the aetiological relevance of vascular disruptions in this previously unreported combination of Möbius, Goldenhar and hypoglossia-hypodactyly anomalies. The concurrence of anomalies in this patient represents an association and not a pleiotropic syndrome.

Rectal atresia as rare manifestation in EEC syndrome.

A newborn boy presented with bilateral split hand/foot malformation, sparse hair, dry and scaly skin, and nasolacrimal duct obstruction. Despite absence of cleft lip or palate, the findings fit the EEC syndrome. Additionally, the boy had rectal atresia. At least six further patients with EEC syndrome and anal atresia (two published, four unpublished) demonstrate, that anorectal malformation is a further, but rare anomaly in EEC syndrome.

Familial arhinia, choanal atresia, and microphthalmia.

We describe two females (aunt and niece) with variable manifestations of arhinia, choanal atresia, microphthalmia, and hypertelorism. In the literature there is only one report on this syndrome in sibs. We hypothesize autosomal dominant inheritance with reduced penetrance.

Ichthyotic and psoriasiform skin lesions along Blaschko's lines in a woman with X-linked dominant chondrodysplasia punctata.

X-linked dominant chondrodysplasia punctata is a rare genodermatosis characterized by transient punctate epiphyseal calcifications and ichthyotic skin changes, usually resolving during early infancy. We describe the case of a 32-year-old woman with ichthyotic skin lesions that developed during early childhood and persisted into adulthood. Psoriasiform skin changes became evident for the first time during adulthood. Both the ichthyotic and psoriasiform skin lesions followed Blaschko's lines. This case is unique because of the coexistence of ichthyotic and psoriasiform skin changes in an adult with X-linked dominant chondrodysplasia punctata.

Monozygotic twins concordant for Rubinstein-Taybi syndrome: changing phenotype during infancy.

We describe monozygotic twin sisters concordant for Rubinstein-Taybi syndrome diagnosed at the age of 10 weeks. The typical features of Rubinstein-Taybi syndrome in early infancy increasingly developed towards the total "Gestalt" at the age of 2 years and 10 months.