Reduced penetrance in a family with X-linked dominant chondrodysplasia punctata

X-linked dominant chondrodysplasia punctata (Conradi-Hünermann disease, CDPX2) is characterised by short stature, stippled epiphyses, cataracts, ichthyosiform erythroderma and patchy alopecia of the scalp. The disorder is caused by mutations within the emopamil binding protein (EBP) gene encoding a 3beta-hydroxysteroid-Delta(8),Delta(7)-isomerase. The intrafamilial variation of disease severity is a known feature of CDPX2 probably caused by skewed X-inactivation. We report on a female fetus with typical symptoms of CDPX2 such as short limbs, postaxial polydactyly, ichthyotic skin lesions and punctate calcifications. Molecular genetic analysis of the EBP gene revealed a nonsense mutation (c.328C>T, p.R110X), which was previously detected in one CDPX2 patient and in a second female patient, who was only affected on one body side and erroneously diagnosed as CHILD syndrome. Surprisingly, the mother of our fetus carries the same mutation without having any signs of CDPX2. X-inactivation studies did not reveal any evidence of skewing neither in the mother nor in the fetus.     

Novel and recurrent EBP mutations in X-linked dominant chondrodysplasia punctata

Chondrodysplasia punctata (CDP) is a heterogeneous group of skeletal dysplasias characterized by stippled epiphyses. A subtype of CDP, X-linked dominant chondrodysplasia punctata (CDPX2), known also as Conradi-Hünermann-Happle syndrome, is a rare skeletal dysplasia characterized by short stature, craniofacial defects, cataracts, ichthyosis, coarse hair, and alopecia. The cause of CDPX2 was unknown until recent identification of mutations in the gene encoding Delta(8),Delta(7) sterol isomerase emopamil-binding protein (EBP). Twelve different EBP mutations have been reported in 14 patients with CDPX2 or unclassified CDP, but with no evidence of correlation between phenotype and nature of the mutation. To characterize additional mutations and investigate possible phenotype-genotype correlation, we sequenced the entire EBP gene in 8 Japanese individuals with CDP; 5 of them presented with a CDPX2 phenotypes. We found EBP mutations in all 5 CDPX2 individuals, but none in non-CDPX2 individuals. Three of these CDPX2 individuals carried novel nonsense mutations in EBPand the other two, separate missense mutations that had been reported also in different ethnic groups. Our results, combined with previous information, suggest all EBP mutations that produce truncated proteins result in typical CDPX2, whereas the phenotypes resulted from missense mutations are not always typical for CDPX2. Patients with nonsense mutations showed abnormal sterol profiles consistent with a defect in Delta(8), Delta(7) sterol isomerase. X-inactivation patterns of the patients showed no skewing, an observation that supports the assumption that inactivation of the EBP gene occurs at random in affected individuals.     

XXY male with X-linked dominant chondrodysplasia punctata (Happle syndrome)

Happle syndrome is an X-linked dominant disorder with presumed lethality in hemizy-gous males; familial occurrence is rare. We describe a family with Happle syndrome affecting individuals in 3 generations. A man in this family is the first known male patient with Happle syndrome. He is severely affected; this may be due to his 47, XXY kary-Otype. © 1995 Wiley-Liss, Inc.     

X-linked dominant chondrodysplasia punctata (CDPX2) caused by single gene mosaicism in a male

Hemophagocytic lymphohistiocytosis (HLH) composes a group of rare heterogenous disorders characterized by uncontrolled accumulation and infiltration of activated T lymphocytes and macrophages. Cytotoxic T and natural killer cell activity is significantly reduced or absent in these patients. Mutations in the important mediator of lymphocyte cytotoxicity perforin were identified in a number of HLH individuals. Here we report a novel missense mutation thr435met in the conserved Ca(2+) binding domain of perforin in a patient with HLH. Prediction of the 3-dimensional structure of the thr435met perforin mutant using comparative molecular modeling indicates that the protein's ability to bind Ca(2+), and therefore its cytolytic function, would be strongly compromised. In addition, this patient exhibited abnormal CD45 splicing caused by a C77G mutation in the gene encoding CD45 (PTPRC). Our findings suggest a combined role for perforin mutation and abnormal CD45 splicing as significant contributory factors in the pathogenesis of HLH.     

Dominant sex-linked inherited chondrodysplasia punctata: a distinct type of chondrodysplasia punctata

This paper suggests that there is probably a dominant, sex-linked type of chondrodysplasia punctata. Clinical data are reported for three girls with such a disorder. Two of their mothers showed a mild form of cicatricial alopecia. The pathognomonic dermatological findings in the children include crythematous skin changes and striated ichthyosiform hyperkeratosis during the first months of life. Later on, patterned ichthyosis, follicular atrophoderma, coarse, lusterless hair and cicatricial alopecia become evident. It is assumed that about one fourth of all cases with chondrodysplasia punctata reported in the literature belong to the dominant sex-linked type.     

Fetus with an unusual form of nonrhizomelic chondrodysplasia punctata: case report and review

Chondrodysplasia punctata (CDP) is a heterogeneous condition mainly characterized by premature and ectopic calcification of cartilage. Many genetic and nongenetic causes have been described leading to a preliminar etiological classification into defects of peroxisomal metabolism, defects in cholesterol metabolism, and vitamin K (vit K) metabolism. However, numerous cases of CDP still remain unclassified. The difficulties in reaching a causal diagnosis are illustrated here by a 23-week-old fetus with nonrhizomelic CDP characterized by extensive cartilage stippling, brachyphalangy, and nasal hypoplasia.     

X-linked recessive chondrodysplasia punctata: spectrum of arylsulfatase E gene mutations and expanded clinical variability

Partial trisomy of the long arm of chromosome 10 is a well-defined but rare syndrome. Clinical features of this chromosomopathy are a distinctive dysmorphic appearance, developmental delay, growth retardation, and in some cases, abnormalities of the extremities and renal, cardiac and ocular anomalies. This report describes a neonate with symmetric growth retardation and multiple dysmorphic features, in whom chromosomal analysis revealed a partial trisomy of chromosome 10q with a monosomy of the 13q34 region. The phenotype shares many common features with previously published cases. In addition to the typical features, our case also shows renal hypoplasia with early renal insufficiency and some genital anomalies.     

Chondrodysplasia punctata: Another possible X-linked recessive case

A 22-week fetus who had died in utero had a markedly hypoplastic nose and other facial abnormalities, short fingers, hypoplastic nails, and small phallus. Radiologically there was symmetrical cartilaginous stippling of the vertebral column, femoral heads, calcanei and elbows typical of chondrodysplasia punctata (CP), and metacarpal shortness and tiny pyramidal phalanges. The several causally different forms of CP are tabulated. Differential diagnosis suggests that the present case, which does not have limb shortness, could be a case of X-linked recessive brachytelephalangic chondrodysplasia punctata. © 1992 Wiley-Liss, Inc.     

Neonatal lupus syndrome: a case with chondrodysplasia punctata and other unusual manifestations.

We report a case of a newborn infant whose mother had systemic lupus erythematosus (SLE) diagnosed before pregnancy. The child had clinical manifestations of neonatal lupus as well as chondrodysplasia punctata and other findings that resemble the congenital anomalies associated with the use of oral anticoagulants, with no history of exposure. We speculate that the combined action of the different maternal autoantibodies may produce the whole spectrum of manifestations.     

Chondrodysplasia punctata: a boy with X-linked recessive chondrodysplasia punctata due to an inherited X-Y translocation with a current classification of these disorders.

Chondrodysplasia punctata (CDP) is a heterogeneous group of rare bone dysplasias characterized by punctate calcification of cartilage. The punctate calcifications are non-specific and have been seen in a wide variety of disorders including the Zellweger syndrome, warfarin, dilantin, alcohol and rubella embryopathies, vitamin-K-epoxide-reductase deficiency, chromosome trisomies 18 and 21, the Smith-Lemli-Opitz syndrome, prenatal infectious chondritis, hypothyroidism, and other rare disorders. We report on a boy with short stature, developmental delay, nasal hypoplasia, telebrachydactyly, hypoplastic genitalia, CDP, ichthyosis, hypoplastic genitalia, and a 46-X,+der(X),t(X;Y)(p22.31;q11.21), Y karyotype. Genomic DNA probe analysis was interpreted as showing that the translocation breakpoint was within the X-linked Kallmann syndrome gene. We review a current classification of these disorders that includes 3 well-defined single gene disorders. These include an autosomal recessive rhizomelic type with early lethality, an X-linked dominant type with presumed male lethality, and an X-linked recessive type that has only been described as part of a contiguous gene deletion syndrome.     

Chondrodysplasia punctata: A boy with X-linked recessive chondrodysplasia punctata due to an inherited X-Y translocation with a current classification of these disorders

Chondrodysplasia punctata (CDP) is a heterogeneous group of rare bone dysplasias characterized by punctate calcification of cartilage. The punctate calcifications are nonspecific and have been seen in a wide variety of disorders including the Zellweger syndrome, warfarin, dilantin, alcohol and rubella embryopathies, vitamin-K-epoxide-reductase deficiency, chromosome trisomies 18 and 21, the Smith-Lemli-Opitz syndrome, prenatal infectious chondritis, hypothyroidism, and other rare disorders. We report on a boy with short stature, developmental delay, nasal hypoplasia, telebrachydactyly, hypoplastic genitalia, CDP, ichthyosis, hypoplastic genitalia, and a 46-X, +der(X),t(X;Y)(p22.31;q11.21), Y karyotype. Genomic DNA probe analysis was interpreted as showing that the translocation breakpoint was within the X-linked Kallmann syndrome gene. We review a current classification of these disorders that includes 3 well-defined single gene disorders. These include an autosomal recessive rhizomelic type with early lethality, an X-linked dominant type with presumed male lethality, and an X-linked recessive type that has only been described as part of a contiguous gene deletion syndrome. © 1992 Wiley-Liss, Inc.     

Chondrodysplasia punctata: another possible X-linked recessive case.

A 22-week fetus who had died in utero had a markedly hypoplastic nose and other facial abnormalities, short fingers, hypoplastic nails, and small phallus. Radiologically there was symmetrical cartilaginous stippling of the vertebral column, femoral heads, calcanei and elbows typical of chondrodysplasia punctata (CP), and metacarpal shortness and tiny pyramidal phalanges. The several causally different forms of CP are tabulated. Differential diagnosis suggests that the present case, which does not have limb shortness, could be a case of X-linked recessive brachytelephalangic chondrodysplasia punctata.     

X-linked dominant chondrodysplasia with platyspondyly, distinctive brachydactyly, hydrocephaly, and microphthalmia

We describe a family with an X-linked dominant chondrodysplasia. Four males and six females were affected through four generations. Identification of skeletal abnormalities and hydrocephaly during the pregnancy of three male fetuses led to termination of the pregnancies. A fourth affected male died at 6 days of life. The four patients had chondrodysplasia, hydrocephaly, and facial features with microphthalmia. Radiographs showed severe platyspondyly and various bone abnormalities including a distinctive metaphyseal cupping of the metacarpals, metatarsals, and phalanges. The affected females were less affected and showed small stature, sometimes associated with body asymmetry and mild mental retardation. This condition appears to be a previously unrecognized X-linked dominant chondrodysplasia.     

Rhizomelic chondrodysplasia punctata and survival beyond one year: a review of the literature and five case reports

Rhizomelic chondrodysplasia punctata (RCDP), a peroxisomal disorder, is considered to be a lethal neonatal autosomal recessive chondrodysplasia. We report five patients, three of whom survived beyond 1 year, and we summarize the findings in 21 patients from a literature review who survived beyond 1 year. In those patients that survive, there is a high association of spasticity, psychomotor retardation, growth failure, seizures, thermoregulatory instability, feeding difficulty, and recurrent otitis media and pneumonia. Three of our five patients had no radiographic evidence of vertebral body clefts, a finding which has previously been considered invariable in RCDP. Three of our patients had distinctive facies that differ from the classic Conradi-Hunermann facies.     

A pregnancy following PGD for X-linked dominant [correction of X-linked autosomal dominant] incontinentia pigmenti (Bloch-Sulzberger syndrome): case report

Incontinentia Pigmenti (Bloch-Sulzberger syndrome) is a rare multisystem, ectodermal disorder associated with dermatological, dental and ocular features, and in <10% of cases, severe neurological deficit. Pedigree review suggests X-linked dominance with lethality in affected males. Presentation in female carriers is variable. Following genetic counselling, a mildly affected female carrier diagnosed in infancy with a de novo mutation was referred for preimplantation sexing, unusually selecting for male gender, with an acceptance of either normality or early miscarriage in an affected male. Following standard in-vitro fertilization and embryo biopsy, fluorescence in situ hybridization (FISH) unambiguously identified two male and two female embryos. A single 8-cell, grade 4 male embryo was replaced. A positive pregnancy test was reported 2 weeks after embryo transfer, although ultrasonography failed to demonstrate a viable pregnancy. Post abortive fetal tissue karyotyping diagnosed a male fetus with trisomy 16. This is an unusual report of preimplantation genetic diagnosis (PGD) being used for selection of males in an X-linked autosomal dominant disorder and demonstrates the value of PGD where amniocentesis or chorion villus sampling followed by abortion is not acceptable to the patient. This case also demonstrates the importance of follow-up prenatal diagnosis.