Expansion and further delineation of the SETD5 phenotype leading to global developmental delay, variable dysmorphic features, and reduced penetrance.

Diagnostic exome sequencing (DES) has aided delineation of the phenotypic spectrum of rare genetic etiologies of intellectual disability (ID). A SET domain containing 5 gene (SETD5) phenotype of ID and dysmorphic features has been previously described in relation to patients with 3p25.3 deletions and in a few individuals with de novo sequence alterations. Herein, we present additional patients with pathogenic SETD5 sequence alterations. The majority of patients in this cohort and previously reported have developmental delay, behavioral/psychiatric issues, and variable hand and skeletal abnormalities. We also present an apparently unaffected carrier mother of an affected individual and a carrier mother with normal intelligence and affected twin sons. We suggest that the phenotype of SETD5 is more complex and variable than previously presented. Therefore, many features and presentations need to be considered when evaluating a patient for SETD5 alterations through DES.

20p11 deletion in a female child with panhypopituitarism, cleft lip and palate, dysmorphic facial features, global developmental delay and seizure disorder.

Deletions of 20p are rare with the majority of reported cases involving individuals with 20p12 deletions associated with Alagille syndrome. We report on a child with a de novo mosaic 20p11 deletion who presents with panhypopituitarism; hypoplastic pituitary gland and ectopic posterior pituitary gland on MRI of the brain; cleft lip and palate; kyphosis with anterior beaking of L1 and L2 vertebral bodies; pulmonic stenosis; dysmorphic facial features including flat nasal bridge, hypoplastic premaxilla, hypotelorism, preauricular pit, and cupped ears; seizure disorder; variable muscle tone; and global developmental delay. Array comparative genomic hybridization revealed this deletion to be approximately 5.4 Mb in size, containing 35 genes. Previously, an infant with 20p11.22 deletion who had panhypopituitarism, craniofacial, and genital abnormalities was reported, but the precise parameters of that deletion are unavailable. Several other reported cases of 20p11 deletions also have phenotypic overlap with our case. The similarities in clinical features of these patients suggest that the genes at 20p11 have a critical role in development of midline brain structures.

Identification of a previously unrecognized microdeletion syndrome of 16q11.2q12.2.

We report the identification of microdeletions of 16q11.2q12.2 by microarray-based comparative genomic hybridization (aCGH) in two individuals. The clinical features of these two individuals include hypotonia, gastroesophageal reflux, ear anomalies, and toe deformities. Other features include developmental delay, mental retardation, hypothyroidism, and seizures. The identification of common clinical features in these two individuals and those of one other report suggests microdeletion of 16q12.1q12.2 is a rare, emerging syndrome. These results illustrate that aCGH is particularly suited to identify rare chromosome abnormalities in patients with apparently non-syndromic idiopathic mental retardation and birth defects.

Identification of two single base substitutions in the UGT1 gene locus which abolish bilirubin uridine diphosphate glucuronosyltransferase activity in vitro.

Accumulating evidence indicates that mutations in the human UGT1 gene locus abolish hepatic bilirubin UDP-glucuronosyltransferase activity and cause the subsequent accumulation of bilirubin to toxic levels in patients with Crigler-Najjar type 1 (CN-I). Genetic and biochemical criteria are required to link CN-I with mutations in UGT1. Here we present analysis of mutations at the UGT1 locus in three individuals that were clinically diagnosed with CN-I (two related and one unrelated). Each patient carries a single base substitution that alters conserved residues in the transferase enzyme molecule, serine to phenylalanine at codon 376 and glycine to glutamic acid at codon 309. Each was homozygous for the defect as demonstrated by sequencing and RFLPs. Mutant cDNAs, constructed by site-directed mutagenesis, inserted into expression vectors, and transfected into COS-1 cells, supported the synthesis of the bilirubin transferase protein but only cells transfected with the wild-type cDNA expressed bilirubin UDP-glucuronosyltransferase activity. The data provide conclusive evidence that alterations at Gly 309 and Ser 376 are the genetic basis for CN-I in these families. These results suggest that the two codons, located in conserved regions of the molecule, are part of the active site of the bilirubin enzyme.

Meningococcal group Y pneumonia in an adolescent female.

Neisseria meningitidis group Y has been considered to be an uncommon pathogen. Meningococcal group Y disease has recently been reported with increased frequency in military training camps coincident with the routine use of meningococcal group C vaccine. Pneumonia produced by the group Y organism may mimic disease caused by common respiratory tract pathogens, and isolation by routine methods may be difficult. A 16-year-old asthmatic female developed lobar pneumonia secondary to N meningitidis group Y while on alternate day steroids. We speculate that neither steroid therapy nor an isolated serum IgA deficiency in the presence of secretory IgA discovered after her recovery predisposed her to sinopulmonary disease. The true incidence of group Y disease is unknown. Awareness of its potential pathogenicity may have clinical significance with the availability of a group Y vaccine.

Computed tomography of the head in the evaluation of microcephaly.

Eighty-five infants and children found to have microcephaly had computed tomographic (CT) brain scans performed. A greater degree of microcephaly correlated with the finding of atrophy or ventricular dilation on CT scan. Patients who had known preceding destructive brain insults had the highest incidence of abnormal findings on scans (20/22). Patients who had CNS dysfunction of unknown etiology had the lowest frequency of abnormal findings (12/33); however, in three of these patients, a previously unsuspected brain malformation was found on CT scan. Patients who had other congenital anomalies had an intermediate proportion of abnormal findings on CT scans (20/30), and in 11 of these scans, a previously unsuspected or only partly suspected brain malformation was diagnosed. Discovering previously unsuspected information or finding supportive data regarding the basis for the underlying disease process, being able to provide a more specific developmental prognosis and accurate genetic counseling, justifies the inclusion of a CT scan of the head in the evaluation of the microcephalic child.

Low-dose intravenous insulin infusion versus subcutaneous insulin injection: a controlled comparative study of diabetic ketoacidosis.

Fourteen paients, 5 to 17 years old, with 18 episodes of uncomplicated diabetic ketoacidosis were randomly allocated and studied prospectively. The study group received 0.1 units of insulin per kilogram of body weight per hour as a continuous intravenous infusion; the control group received insulin subcutaneously. In both groups, a gradual fall in serum glucose and ketone levels was achieved. Serum ketones persisted longer in the intravenous group. No complications were encountered. The study suggests that both regimens of insulin administration are equally effective, but a low-dose constant infusion may provide more simplified and controlled management than the standard subcutaneous regimen.

Anophthalmia, intracerebral cysts, and cleft lip/palate: expansion of the phenotype in oculocerebrocutaneous syndrome?

We report on a patient with multiple congenital anomalies including anophthalmia, cleft lip and palate, and central nervous system anomalies similar to the case reported by Leichtman et al. [1994: Am J Med Genet 50:39-41] and to oculocerebrocutaneous (Delleman) syndrome. Although the two cases and those with oculocerebrocutaneous syndrome may represent separate but overlapping entities, our patient and the case described by Leichtman et al. [1994: Am J Med Genet 50:39-41] may represent a more severe form of oculocerebrocutaneous syndrome.

Expansion of the phenotype in Hennekam syndrome: a case with new manifestations.

We report on a female with lymphedema, facial anomalies, intestinal lymphangiectasia, and moderate mental retardation consistent with the diagnosis of Hennekam syndrome. In addition, she had a number of other anomalies not previously described in this autosomal recessive disorder, including a congenital heart defect, atretic ear canals, vesicoureteral reflux, and rectal prolapse.

Forearm fullness in Coffin-Lowry syndrome: a misleading yet possible early diagnostic clue.

Two unrelated infants with delayed development and suspected abnormalities of the upper limbs were found to have the Coffin-Lowry syndrome. Both had marked fullness of the forearms in the presence of normal skeletal structures which resulted from increased subcutaneous fat. Although initially misleading, the forearm changes may serve as an early diagnostic clue in this disorder.

Case of partial duplication 2q3 with characteristic phenotype: rare occurrence of an unbalanced offspring resulting from a parental pericentric inversion.

We report on a male infant with partial trisomy 2q (q34-->qter) resulting from a maternal pericentric inversion of chromosome 2 (p25. 2q34). The infant had clinical findings similar to the characteristic phenotype associated with a partial duplication of chromosome 2q3. Carriers of pericentric inversions of chromosome 2 have an increased risk of pregnancy loss but have only rarely been reported to have a liveborn offspring with an unbalanced chromosome constitution. This case further confirms the risks associated with a pericentric inversion of chromosome 2 and is the second report with manifestations of the trisomy 2q3 phenotype.

Humero-radio-ulnar synostosis: a new case and review.

We report on a patient with humero-radio-ulnar synostosis and upper limb oligoectrosyndactyly. All cases have been sporadic including discordance in monozygotic twins, and similar findings have occurred in thalidomide embryopathy. Further observations of similarly affected patients are needed to elucidate the nature of this upper limb defect and its cause.

XY gonadal dysgenesis associated with a multiple pterygium syndrome phenotype.

Most phenotypic females with an XY male karyotype do not have significant extragenital anomalies; however, some patients with additional abnormalities have been described. We report on an individual with XY gonadal dysgenesis, mental retardation, microcephaly, growth retardation, and multiple pterygia. Although not previously reported, the possible relationship between these findings is discussed in the context of evident heterogeneity of XY gonadal dysgenesis.

Otocephaly-midline malformation association.

Otocephaly ("agnathia") is a developmental field complex with structural defects limited to the craniofacial region. Previously, two infants with otocephaly, situs inversus totalis, renal defects, and vertebral and rib abnormalities were reported by Pauli et al. [Teratology 23:85-93, 1981]. We describe a similarly affected infant male, supporting the existence of this midline malformation association. A generalized disturbance in cell migration from the primitive streak may be its pathogenesis. A search for additional patients among cases of otocephaly may establish its prevalence, patterns of associated anomalies, and cause.

Changing phenotype in Floating-Harbor syndrome.

We report on a girl with Floating-Harbor syndrome, trigonocephaly due to metopic suture synostosis, preauricular pit, hypoplastic thumb, subluxated radial head, and Sprengel deformity. A review suggests that trigonocephaly may be an important craniofacial manifestation in this syndrome that is recognizable in infancy. With time, this finding appears to become less noticeable, and the face develops a triangular shape, accentuated by a broad and bulbous nose.

Metacarpophalangeal pattern profile analysis in Sotos syndrome.

The metacarpophalangeal pattern profile (MCPP) was analyzed on 16 Sotos syndrome patients. A mean Sotos syndrome profile was produced. Correlation studies confirm clinical homogeneity of Sotos syndrome individuals. Discriminant analysis of Sotos syndrome patients and normal individuals produces a function of two MCPP variables and age, which may provide a useful tool for diagnosis.

Restriction fragment length polymorphisms within proximal 15q and their use in molecular cytogenetics and the Prader-Willi syndrome.

Restriction fragment length polymorphisms (RFLPs) are described in detail for 6 DNA probes (D15S9-13, D15S18) that localize to the proximal long arm of human chromosome 15 (15q11-15q13: this report and Tantravahi et al., Am. J. Med. Genet. 33:78-87. Multiple RFLPs are detected by the probe that identifies locus D15S13, and these RFLPs are shown by genomic mapping to result from a nearby insertion or deletion of 1.8 kilobases (kb) of DNA. This set of RFLPs detected by proximal 15q probes can be used for studies on the Prader-Willi syndrome (PWS) and on mentally retarded individuals with a supernumerary inv dup(15) chromosome. Five of the polymorphic loci (D15S9-13) map to the region implicated in the cause of the PWS (15q11.2-15q12). Each of 4 families tested with these probes, as well as an additional "PWS-like" patient, was informative by RFLP analysis. The two PWS deletions studied, which occurred de novo, were inherited from the chromosome 15 provided by the father. By contrast, the 2 inv dup(15) chromosomes analyzed were of maternal origin. The use of RFLPs can also simplify the molecular determination of copy number in chromosomal aneuploidy, as exemplified by analysis of individuals with the PWS and a deletion, patients with an inv dup(15), and one patient with a more complex rearrangement involving chromosome 15. Our studies demonstrate the application of DNA probes for both molecular cytogenetic studies on this chromosome region and the development of diagnostic molecular markers to aid early clinical diagnosis of the PWS.

Mirror image duplication of the hands and feet: report of a sporadic case with multiple congenital anomalies.

Mirror image duplication of the hands and feet is a rare entity. Based on 3 previous reports, findings include nasal abnormalities, dimelia of ulna and fibula, tibial hypoplasia and mirror image duplication of hands and feet. We report on a sporadic case in which mirror image duplication was associated with multiple congenital anomalies. Although these cases may represent variable expression of the same dominantly transmitted complex polysyndactyly syndrome, it is possible that mirror image duplication of the hands and feet is a manifestation common to a number of distinct clinical entities. During limb bud development, duplication and aberrant positioning of the zone of polarizing activity in relation to the apical ectodermal ridge may account for the anatomic abnormalities of the hands and feet in these patients.

Microcephalic osteodysplastic dysplasia.

We present two patients with a distinct facial phenotype, short stature, brachydactyly, clubfoot deformities, cataracts, microcephaly, and normal intelligence. Similar radiographic abnormalities of the spine, long bones, hands, and feet were noted. These patients are similar to 2 males previously described by Saul and Wilson [1990: Am J Med Genet 35:388-393]. These 4 patients appear to have a unique skeletal dysplasia characterized by microcephaly, distinct facial phenotype, multisystem abnormalities, and short stature of postnatal onset.

Sternal malformation/vascular dysplasia association.

Sternal defects associated with superficial craniofacial vascular lesions are rare. We report on two additional patients with a sternal cleft and cutaneous, craniofacial hemangiomata to emphasize that this unusual combination of findings represents a recognizable sternal malformation/vascular dysplasia association. In addition, internal vascular lesions were also identified in these individuals, in one instance involving the upper respiratory tract and in the other the viscera. Although the pathogenesis of these findings is unclear, an early disturbance affecting midline mesodermal structures leading to lack of complete fusion of lateral sternal bands and overlying cutaneous tissue, or deficient formation of a proposed medioventral unpaired structure which may be involved in the formation of the sternum, and persistence and proliferation of midline angioblastic tissue may be possible mechanisms during the sixth to ninth gestational weeks. To date, all but one of the 15 known cases have been sporadic and no teratogen has been identified as a cause for these clinical manifestations. The presence of this association should signal the need to search for potentially life-threatening internal hemangiomata.