Search

We report the case of a child with partial trisomy of the short arm of chromosome 17, which was characterized by 24-color spectral karyotyping (SKY) and other fluorescence in situ hybridization (FISH) methods. The child had phenotypic features previously associated with trisomy 17p, including facial characteristics, developmental delay, postnatal growth retardation, single transverse crease, inguinal hernia, redundant neck skin folds, congenital heart defect, and club foot. This case illustrates the power of SKY for characterizing derivative/marker chromosomes in patients with rare cytogenetic syndromes.

We describe the clinical characteristics of a provisionally unique form of distal arthrogryposis. The anomalies observed in affected individuals are more severe than those in distal arthrogryposis type 1 and are similar to but less dramatic than those described in distal arthrogryposis type 2A (Freeman-Sheldon syndrome). Consequently, we label this disorder distal arthrogryposis type 2B (DA2B). Affected individuals have vertical talus, ulnar deviation, severe camptodactyly, and a distinctive face characterized by a triangular shape, prominent nasolabial folds, downslanting palpebral fissures, small mouth, and a prominent chin. A gene for DA2B maps to chromosome 11p15.5. We suggest that DA2B is partly responsible for the clinical variability observed in Freeman-Sheldon syndrome.

The oral-facial-digital syndromes (OFDS) have in common minor facial and oral anomalies (including tongue lobulation and/ or hamartomas, accessory frenula, and alveolar anomalies) and variable digital defects such as polydactyly. The classification based on the presence of additional findings [Toriello, 1988, 1993] is not perfect, as many reported examples of a particular OFDS have some other condition. Here we describe six children, all diagnosed as having OFDS IV (OFDS with tibial defects), whose manifestations illustrate the apparent genetic heterogeneity.

The ulnar-mammary syndrome (UMS) is an autosomal dominant disorder characterized by posterior limb deficiencies or duplications, apocrine/mammary gland hypoplasia and/or dysfunction, abnormal dentition, delayed puberty in males, and genital anomalies. We present the clinical descriptions of 33 members of a six generation kindred with UMS. The number of affected individuals in this family is more than the sum of all previously reported cases of UMS. The clinical expression of UMS is highly variable. While most patients have limb deficiencies, the range of abnormalities extends from hypoplasia of the terminal phalanx of the 5th digit to complete absence of the ulna and 3rd, 4th, and 5th digits. Moreover, affected individuals may have posterior digital duplications with or without contralateral limb deficiencies. Apocrine gland abnormalities range from diminished axillary perspiration with normal breast development and lactation, to complete absence of the breasts and no axillary perspiration. Dental abnormalities include misplaced or absent teeth. Affected males consistently undergo delayed puberty, and both sexes have diminished to absent axillary hair. Imperforate hymen were seen in some affected women. A gene for UMS was mapped to chromosome area 12q23-q24.1. A mutation in the gene causing UMS can interfere with limb patterning in the proximal/distal, anterior/posterior, and dorsal/ventral axes. This mutation disturbs development of the posterior elements of forearm, wrist, and hand while growth and development of the anterior elements remain normal.

We studied a male patient with de novo pure trisomy 12p syndrome by molecular analysis and fluorescence in situ hybridization (FISH) with markers from chromosome 12. G-banding studies demonstrated a 46,XY, 22p+ karyotype and the banding pattern and clinical findings suggested that the extra chromosomal material was derived from 12p. Trisomy 12p was confirmed by dosage analysis with chromosome 12p markers and FISH analysis with a whole chromosome 12 paint. The de novo re-arranged chromosome was of paternal origin. A comparison of the clinical and cytogenetic findings in this patient was made with previously described cases of trisomy 12p. We propose a classification system for 12p trisomy in order to better characterize the correlative relationships between specific cytogenetic constitution and phenotype.

Williams syndrome (WS) is generally characterized by mental deficiency, gregarious personality, dysmorphic facies, supravalvular aortic stenosis, and idiopathic infantile hypercalcemia. Patients with WS show allelic loss of elastin (ELN), exhibiting a submicroscopic deletion, at 7q11.23, detectable by FISH. Hemizygosity is likely the cause of vascular abnormalities in WS patients. A series of 235 patients was studied, and molecular cytogenetic deletions were seen in 96% of patients with classic WS. Patients included 195 solicited through the Williams Syndrome Association (WSA), plus 40 clinical cytogenetics cases referred by primary-care physicians. Photographs and medical records of most WSA subjects were reviewed, and patients were identified as "classic" (n = 114) or "uncertain" (n = 39). An additional 42 WSA patients were evaluated without clinical information. FISH was performed with biotinylated ELN cosmids on metaphase cells from immortalized lymphoblastoid lines from WSA patients and after high-resolution banding analysis on clinical referral patients. An alpha-satellite probe for chromosome 7 was included in hybridizations, as an internal control. Ninety-six percent of the patients with classic WS showed a deletion in one ELN allele; four of these did not show a deletion. Of the uncertain WS patients, only 3 of 39 showed a deletion. Of the 42 who were not classified phenotypically, because of lack of clinical information, 25 patients (60%) showed a deletion. Thirty-eight percent (15/40) of clinical cytogenetics cases showed an ELN deletion and no cytogenetic deletion by banded analysis. These results support the usefulness of FISH for the detection of elastin deletions as an initial diagnostic assay for WS.

We present two female children with a distinctive pattern of malformation, including persistent thrombocytopenia, Robin sequence, agenesis of the corpus callosum, distinctive facies and developmental delay. We feel that these findings constitute a heretofore undescribed syndrome. Patient 1 presented during the newborn period with thrombocytopenia, Robin cleft, distinctive facies and agencies of the corpus callosum. Her thrombocytopenia has been persistent. Bone marrow aspirate showed adequate megakaryocytes. On follow-up she has mental retardation, microcephaly, growth delay and enamel hypoplasia. Patient 2 was also noted during the newborn period to have the Robin sequence, agenesis of the corpus callosum, a similar face to case 1 and persistent thrombocytopenia. Bone marrow aspirate showed decreased megakaryocytes. She also had delayed development, short stature, microcephaly and enamel hypoplasia. The combination of the Robin cleft, congenital onset of persistent thrombocytopenia and enamel hypoplasia appears particularly unique in combination. The aetiopathogenesis of this condition is unknown.

Nonteratomatous intrapulmonary neuroglial heterotopia not associated with birth trauma or frank vascular embolization has been described rarely. This article briefly reviews the literature, and presents two additional cases of intrapulmonary neuroglial heterotopia. We found 14 cases in the literature. Twelve of these cases had central nervous system disruption, where neuroglial elements were in direct contact with amniotic fluid. Several hypotheses have been proposed, including fetal aspiration of detached neural fragments within amniotic fluid, neural crest migration defects, and vascular embolization with implantation. Of our two cases, one represents the first occurrence where central nervous system abnormalities were secondary to mechanical disruption, rather than to a primary neural tube defect. Our second case represents the youngest documented occurrence (17 weeks gestation) of intrapulmonary neuroglial heterotopia. Additionally, immunohistochemical studies were performed on these lesions, the results of which favor their neural origin. We present these findings and suggest they support the aspiration mechanism for neuroglial heterotopia in lung tissue.

Two patients with the Marshall-Smith syndrome are described. Both had significant and fatal respiratory distress attributable to this condition. Congenital, functional, and acquired abnormalities of the respiratory tract are described in nine of the 11 case reports in the literature and are characteristic of this syndrome as well as a primary cause of failure to thrive and death in these patients. Unusual immunologic findings in one of our two patients are the first to be reported in the Marshall-Smith syndrome. Quantitation of immune function in other patients with this condition will be helpful in determining the significance of these results. It is hoped that the etiology of the syndrome will be discovered as more cases are recognized and reported by pediatricians caring for infants with failure to thrive, advanced bone age, and chronic respiratory symptomatology.

Nine children with a partial deletion of the short arm of the number 10 chromosome have been described in the medical literature. In two new cases of 10p-, the children have several features in common with those previously reported; these features include down-slanting short palpebral fissures, ear anomalies, anteverted nostrils, a short neck, and psychomotor delay. At this stage in the delineation of this condition, the phenotypic expression is variable. However, the craniofacial features of the two children with recently reported 10p- and others display a constellation of individually nonspecific but consistent findings that together form a recognizable gestalt. Pediatric practitioners should consider performing karyotypes in children with developmental disabilities accompanied by multiple structural defects and/or multiple physical variations not part of the family background.

The Miller-Dieker syndrome (MDS), a syndrome with lissencephaly, distinctive craniofacial features, growth impairment, and profound developmental failure, has been associated with a deletion of the distal part of chromosome band 17p13. A minority of patients with the syndrome do not have a deletion detectable with current cytogenetic techniques. Using three highly polymorphic DNA probes (pYNZ22, pYNH37.3, and p144D6) we have detected microdeletions in three MDS patients, two of whom had no visible abnormalities of chromosome 17. Loci defined by two of the DNA probes, pYNZ22 and pYNH37.3, were deleted in all three patients. The most distal locus, defined by p144D6, was present in one MDS patient, possibly defining the distal limits of the MDS region in band 17pl3.3. None of these loci were absent in one case of lissencephaly without MDS.