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.     

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.     

Chondrodysplasia punctata in an infant with duplication 16p due to a 7;16 translocation

This paper describes a newborn with a number of clinical manifestations compatible with duplication 16p due to a 46, XY, -7, +der (7), t(7;16) (p22;p13) pat karyotype. In addition, the baby had chondrodysplasia punctata, whose distribution of lesions did not match any of the well-documented forms of these disorders. The baby also had microcornea and lacked a gallbladder, two features, in addition to chondrodysplasia punctata, that have not previously been noted in cases of duplication 16p.     

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.     

Umbilical cord hernia in a child with autosomal recessive chondrodysplasia punctata.

An infant with congenital chondrodysplasia punctata with a secondary deformation of umbilical cord hernia is reported. The paper discusses deformation syndromes as anomalies due to unusual mechanical or intrinsic factors.     

Identification of an unbalanced X-autosome translocation by array CGH in a boy with a syndromic form of chondrodysplasia punctata brachytelephalangic type

Screening of a large series of patients with unexplained mental retardation with a 1 Mb BAC array resulted in the detection of several cryptic chromosomal imbalances. In this paper we present the findings of array CGH screening in a 14-year-old boy with the brachytelephalangic type of chondrodysplasia punctata, mental retardation and obesity. On several occasions, cytogenetic analysis of this boy revealed a normal karyotype. Subsequent screening with array CGH resulted in the detection of a distal 9p trisomy and distal Xp nullisomy caused by an unbalanced X;9 translocation: 46,Y,der(X)t(X;9)(p22.32;p23). The identification of this de novo chromosomal rearrangement not only made accurate genetic counselling possible but also explained most of the phenotypic abnormalities observed in this patient. This study confirms the power of array CGH in the detection of subtle or submicroscopic chromosomal changes.     

Contiguous gene syndrome due to an interstitial deletion in Xp22.3 in a boy with ichthyosis, chondrodysplasia punctata, mental retardation and ADHD

Microdeletions of Xp22.3 can result in contiguous gene syndromes, showing the variable association of apparently unrelated clinical manifestations such as ichthyosis, chondrodysplasia punctata, hypogonadotropic hypogonadism, anosmia, ocular albinism, short stature and mental retardation. We report on a boy with ichthyosis, dysmorphic features and mental retardation with ADHD. The patient was born at term after a pregnancy complicated by threatened abortion; decreased fetal movements and low estriol serum levels were reported during the last trimester. The boy was referred to us at the age of 13 years. He presented with aggressive and hyperactive behavior. He had dry hair, a flat face, bilateral lens opacities, a small nose with hypoplastic tip, alae nasi and nares, a high-arched palate with a very small cleft, mixed dentition with 7 unerupted permanent teeth, left sensorineural and right mixed hearing loss with a calcified plaque of the tympanic membrane, marked shortness of terminal phalanges of hands and feet, ichthyosis of trunk and limbs. The genomic interval between AFM248th5 and KAL1 was investigated. PCR analysis showed a deletion in Xp22.3, with the distal breakpoint between the marker AFM248th5 and PABX and the proximal one between DXS278 and KAL1. Array-CGH and FISH analysis confirmed the interstitial deletion (of about 5.5 Mb) and refined the breakpoints. We discuss the phenotype of our patient in relationship to the deleted segment and the possibility of mental retardation and ADHD genes in the region.     

Inherited chondrodysplasia punctata due to a deletion of the terminal short arm of an X chromosome

We studied two families with an inherited deletion of the short arm of an X chromosome (Xp) in which affected male offspring have epiphyseal stippling in infancy (chondrodysplasia punctata), nasal hypoplasia, ichthyosis, and mental retardation. The presence of ichthyosis and the apparent pattern of X-linked recessive inheritance prompted investigation of the short arm of the X chromosome through studies of genetic markers and focused cytogenetic analysis. Biochemical studies suggested that there was a deletion of three genes previously mapped to the X-chromosome short arm, including the steroid sulfatase locus, the Xg locus, and the M1C2X locus. Prometaphase chromosomes demonstrated a deletion of Xp at p22.32 in the affected boys, in their obligate-carrier mothers, and in 11 of 25 women at risk as potential carriers. The women carrying the Xp deletion had normal gonadal function and fertility but were shorter than the noncarriers in their families (P less than 0.00001). These findings have implications for the genetic organization of this portion of the human X chromosome and demonstrate that small cytogenetic abnormalities may account for disorders with apparent mendelian patterns of inheritance.     

X/Y translocation in a family with X-linked ichthyosis, chondrodysplasia punctata, and mental retardation: DNA analysis reveals deletion of the steroid sulphatase gene and translocation of its Y pseudogene

We describe a family with two male members showing an X/Y translocation (karyotype: 46,Y,der(X)t(X;Y)(p22;q11]. At physical examination both patients showed ichthyosis, mental retardation and dysmorphic features. Chondrodysplasia punctata and short stature were present in one case. Direct DNA analysis, using a steroid sulphatase cDNA probe, was performed in one patient, his mother and sister, both carriers of the translocation. We found that the translocated region of the Y chromosome includes the steroid sulphatase pseudogene. These results suggest that in our patients the X/Y translocation may be derived from a recombinational event between homologous regions located on the short arm of the X chromosome and the long arm of the Y chromosome. Clinical and molecular studies on the present family add further information for the construction of a tentative physical map of the distal Xp.     

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.     

Deletion of the distal short arm of the X chromosome (Xp) in a patient with short stature, chondrodysplasia punctata, and X-linked ichthyosis due to steroid sulfatase deficiency.

We observed a boy with short stature, chondrodysplasia punctata, ichthyosis, and a terminal deletion of Xp. Steroid sulfatase deficiency was demonstrated in the patient's fibroblasts. Molecular analysis showed a deletion of the entire steroid sulfatase gene. This case represents another example of a contiguous gene syndrome in which the co-deletion of adjacent genes on a chromosome is responsible for a complex phenotype.     

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.     

Deletion of the distal short arm of the X chromosome (Xp) in a patient with short stature,chondrodysplasia punctata,and X-linked ichthyosis due to steroid sulfatase deficiency

We observed a boy with short stature, chondrodysplasia punctata, ichthyosis, and a terminal deletion of Xp. Steroid sulfatase deficiency was demonstrated in the patient's fibroblasts. Molecular analysis showed a deletion of the entire steroid sulfatase gene. This case represents another example of a contiguous gene syndrome in which the co-deletion of adjacent genes on a chromosome is responsible for a complex phenotype.     

A 45,X male with an X;Y translocation: implications for the mapping of the genes responsible for the mapping of the genes responsible for Turner syndrome and X-linked chondrodysplasia punctata

In a male patient with a 45,X karyotype, the terminal part ofthe Y chromosome short arm was translocated as a single blockon to the X chromosome. This rearranged X chromosome was, inevery regard, the same as that present in XX males resultingfrom an abnormal X-Y interchange. Correlations between the phenotypeof this patient and the extent of the deletions on the X andY chromosomes allowed us to map the genes responsible for mostfeatures of the Turner syndrome between DXS432 and Xqter onthe X chromosome, and the homologous Y genes either on Yp ininterval 4 or on Yq. The molecular analysis of this X-Y translocationallowed us also to reduce the interval for the X-linked recessivechondrodysplasia punctata gene to a 1.5 Mb interval betweenDXS432 and DXS31.     

Triplication of chromosome arm 20p due to inherited translocation and secondary nondisjunction.

A patient with triplication of all of chromosome arm 20p is presented to illustrate the relatively modest degree of developmental delay that can result from autosomal triplication and the role of nondisjunction as a mechanism for deriving a partial triplication status.     

A lethal skeletal dysplasia with features of chondrodysplasia punctata and osteogenesis imperfecta: an example of Astley-Kendall dysplasia. Further delineation of a rare genetic disorder.

An unusual osteochondrodysplasia presenting with lethal neonatal short limbed dwarfism, defective ossification, and punctate calcification within cartilage is presented. The features resemble four cases previously described with Astley-Kendall dysplasia.