A Newborn Infant with Congenital Central Hypoventilation Syndrome and Pupillary Abnormalities: A Literature Review

We present a neonate with early onset apnea and bradycardia in the absence of primary cardiorespiratory and central nervous system disorders that eventually required chronic ventilator support starting at 6 hours of life. Molecular testing of paired-like homeobox 2b (PHOX2B) gene mutation confirmed the diagnosis of congenital central hypoventilation syndrome (CCHS). CCHS is a rare genetic disorder characterized by impaired central respiratory control with or without broad spectrum of autonomic nervous system (ANS) dysregulations. Ocular ANS dysregulation is a rare finding in CCHS individuals, and it is usually discovered later in life. However, the ophthalmic evaluation of this neonate on first day of life revealed persistent mild dilated oval pupils with limited light reactivity.

Case Report: An Infant With Kabuki Syndrome, Alobar Holoprosencephaly and Truncus Arteriosus: A Case for Whole Exome Sequencing in Neonates With Congenital Anomalies

Kabuki syndrome is a rare multiple anomalies syndrome associated with mutations in KMT2D or KDM6A. It is characterized by infantile hypotonia, developmental delay and/or intellectual disability, long palpebral fissures with everted lateral third of the lower eyelids and typical facial features. Intracranial anomalies occur infrequently in patients with KS and holoprosencephaly has only been recently described. Additionally, though congenital heart diseases are common in patients with KS, to our knowledge truncus arteriosus has never been reported in a patient with KS. We present an unusual case of KS in an infant with holoprosencephaly and truncus arteriosus with partial anomalous pulmonary venous return. Duo whole exome sequencing in our patient identified a pathogenic nonsense variant in exon 10 of KMT2D (c.2782C > T; p. Gln928*) establishing the diagnosis. This report further expands the phenotypic spectrum of patients with Kabuki syndrome and emphasizes the utility of performing large scale sequencing in neonates with multiple congenital anomalies.

Effect of Whole-Genome Sequencing on the Clinical Management of Acutely Ill Infants With Suspected Genetic Disease: A Randomized Clinical Trial

IMPORTANCE

Whole-genome sequencing (WGS) shows promise as a first-line genetic test for acutely ill infants, but widespread adoption and implementation requires evidence of an effect on clinical management.

OBJECTIVE

To determine the effect of WGS on clinical management in a racially and ethnically diverse and geographically distributed population of acutely ill infants in the US.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, time-delayed clinical trial enrolled participants from September 11, 2017, to April 30, 2019, with an observation period extending to July 2, 2019. The study was conducted at 5 US academic medical centers and affiliated children's hospitals. Participants included infants aged between 0 and 120 days who were admitted to an intensive care unit with a suspected genetic disease. Data were analyzed from January 14 to August 20, 2020.

INTERVENTIONS

Patients were randomized to receive clinical WGS results 15 days (early) or 60 days (delayed) after enrollment, with the observation period extending to 90 days. Usual care was continued throughout the study.

MAIN OUTCOMES AND MEASURES

The main outcome was the difference in the proportion of infants in the early and delayed groups who received a change of management (COM) 60 days after enrollment. Additional outcome measures included WGS diagnostic efficacy, within-group COM at 90 days, length of hospital stay, and mortality.

RESULTS

A total of 354 infants were randomized to the early (n = 176) or delayed (n = 178) arms. The mean participant age was 15 days (IQR, 7-32 days); 201 participants (56.8%) were boys; 19 (5.4%) were Asian; 47 (13.3%) were Black; 250 (70.6%) were White; and 38 (10.7%) were of other race. At 60 days, twice as many infants in the early group vs the delayed group received a COM (34 of 161 [21.1%; 95% CI, 15.1%-28.2%] vs 17 of 165 [10.3%; 95% CI, 6.1%-16.0%]; P = .009; odds ratio, 2.3; 95% CI, 1.22-4.32) and a molecular diagnosis (55 of 176 [31.0%; 95% CI, 24.5%-38.7%] vs 27 of 178 [15.0%; 95% CI, 10.2%-21.3%]; P < .001). At 90 days, the delayed group showed a doubling of COM (to 45 of 161 [28.0%; 95% CI, 21.2%-35.6%]) and diagnostic efficacy (to 56 of 178 [31.0%; 95% CI, 24.7%-38.8%]). The most frequent COMs across the observation window were subspecialty referrals (39 of 354; 11%), surgery or other invasive procedures (17 of 354; 4%), condition-specific medications (9 of 354; 2%), or other supportive alterations in medication (12 of 354; 3%). No differences in length of stay or survival were observed.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, for acutely ill infants in an intensive care unit, introduction of WGS was associated with a significant increase in focused clinical management compared with usual care. Access to first-line WGS may reduce health care disparities by enabling diagnostic equity. These data support WGS adoption and implementation in this population.

TRAIL REGISTRATION

ClinicalTrials.gov Identifier: NCT03290469.

Expanding the phenotype, genotype and biochemical knowledge of ALG3-CDG

Congenital disorders of glycosylation (CDGs) are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid biosynthesis that cause multisystem diseases. Individuals with ALG3-CDG frequently exhibit severe neurological involvement (epilepsy, microcephaly, and hypotonia), ocular anomalies, dysmorphic features, skeletal anomalies, and feeding difficulties. We present 10 unreported individuals diagnosed with ALG3-CDG based on molecular and biochemical testing with 11 novel variants in ALG3, bringing the total to 40 reported individuals. In addition to the typical multisystem disease seen in ALG3-CDG, we expand the symptomatology of ALG3-CDG to now include endocrine abnormalities, neural tube defects, mild aortic root dilatation, immunodeficiency, and renal anomalies. N-glycan analyses of these individuals showed combined deficiencies of hybrid glycans and glycan extension beyond Man₅ GlcNAc₂ consistent with their truncated lipid-linked precursor oligosaccharides. This spectrum of N-glycan changes is unique to ALG3-CDG. These expanded features of ALG3-CDG facilitate diagnosis and suggest that optimal management should include baseline endocrine, renal, cardiac, and immunological evaluation at the time of diagnosis and with ongoing monitoring.

Kagami-Ogata Syndrome: Case Series and Review of Literature

Kagami-Ogata syndrome (KOS) (OMIM #608149) is a genetic imprinting disorder affecting chromosome 14 that results in a characteristic phenotype consisting of typical facial features, skeletal abnormalities including rib abnormalities described as "coat hanger ribs," respiratory distress, abdominal wall defects, polyhydramnios, and developmental delay. First identified by Wang et al in 1991, over 80 cases of KOS have been reported in the literature. KOS, however, continues to remain a rare and potentially underdiagnosed disorder. In this report, we describe two unrelated male infants with differing initial presentations who were both found to have the characteristic "coat hanger" rib appearance on chest X-ray, raising suspicion for KOS. Molecular testing confirmed KOS in each case. In addition to these new cases, we reviewed the existing cases reported in literature. Presence of polyhydramnios, small thorax, curved ribs, and abdominal wall defects must alert the perinatologist toward the possibility of KOS to facilitate appropriate molecular testing. The overall prognosis of KOS remains poor. Early diagnosis allows for counseling by a multidisciplinary team and enables parents to make informed decisions regarding both pregnancy management and postnatal care.

Expanding the spectrum of CEP55-associated disease to viable phenotypes

Homozygosity for nonsense variants in CEP55 has been associated with a lethal condition characterized by multinucleated neurons, anhydramnios, renal dysplasia, cerebellar hypoplasia, and hydranencephaly (MARCH syndrome) also known as Meckel-like syndrome. Missense variants in CEP55 have not previously been reported in association with disease. Here we describe seven living individuals from five families with biallelic CEP55 variants. Four unrelated individuals with microcephaly, speech delays, and bilateral toe syndactyly all have a common CEP55 variant c.70G>A p.(Glu24Lys) in trans with nonsense variants. Three siblings are homozygous for a consensus splice site variant near the end of the gene. These affected girls all have severely delayed development, microcephaly, and varying degrees of lissencephaly/pachygyria. Here we compare our seven patients with three previously reported families with a prenatal lethal phenotype (MARCH syndrome/Meckel-like syndrome) due to homozygous CEP55 nonsense variants. Our series suggests that individuals with compound heterozygosity for nonsense and missense variants in CEP55 have a different viable phenotype. We show that homozygosity for a splice variant near the end of the CEP55 gene is also compatible with life.

Clinical spectrum of individuals with pathogenic NF1 missense variants affecting p.Met1149, p.Arg1276, and p.Lys1423: genotype-phenotype study in neurofibromatosis type 1

We report 281 individuals carrying a pathogenic recurrent NF1 missense variant at p.Met1149, p.Arg1276, or p.Lys1423, representing three nontruncating NF1 hotspots in the University of Alabama at Birmingham (UAB) cohort, together identified in 1.8% of unrelated NF1 individuals. About 25% (95% confidence interval: 20.5-31.2%) of individuals heterozygous for a pathogenic NF1 p.Met1149, p.Arg1276, or p.Lys1423 missense variant had a Noonan-like phenotype, which is significantly more compared with the "classic" NF1-affected cohorts (all p < .0001). Furthermore, p.Arg1276 and p.Lys1423 pathogenic missense variants were associated with a high prevalence of cardiovascular abnormalities, including pulmonic stenosis (all p < .0001), while p.Arg1276 variants had a high prevalence of symptomatic spinal neurofibromas (p < .0001) compared with "classic" NF1-affected cohorts. However, p.Met1149-positive individuals had a mild phenotype, characterized mainly by pigmentary manifestations without externally visible plexiform neurofibromas, symptomatic spinal neurofibromas or symptomatic optic pathway gliomas. As up to 0.4% of unrelated individuals in the UAB cohort carries a p.Met1149 missense variant, this finding will contribute to more accurate stratification of a significant number of NF1 individuals. Although clinically relevant genotype-phenotype correlations are rare in NF1, each affecting only a small percentage of individuals, together they impact counseling and management of a significant number of the NF1 population.

Neonatal Hospital Course and Outcomes of Live-born Infants with Trisomy 18 at Two Tertiary Care Centers in the United States

Objectives Trisomy 18 is presumed to be a lethal chromosomal abnormality; medical management of infants with this aneuploidy is controversial. Our objective was to describe our approach and experience with trisomy 18 infants. Study Design We reviewed the initial hospital course, management, and factors predicting discharge from the hospital from two large tertiary care neonatal intensive care units in the southern United States over 26 years. Results Of the 29 infants with trisomy 18, 21 (72%) died in the hospital and 8 (28%) were discharged home. 19 (66%) infants received mechanical ventilation and 10 (34%) received inotropic medications. Eight infants had critical congenital heart defects; only one survived to discharge. Three infants underwent major surgeries; one cardiac surgery, one tracheoesophageal fistula repair, and one myelomeningocele repair. Median length of hospital stay was 14 days (range, 0-78) for all the infants and 31 days (range, 18-66) for those that were discharged home. Factors associated with discharge from the hospital were female sex, higher gestational age, and absence of critical congenital heart defects. Median survival time was 13 days and was significantly longer for females compared with males. Our 1-month and 1-year survival rates were 31% and 3.9% respectively. Conclusion A significant proportion of infants with trisomy 18 were discharged home. These data are helpful in counseling parents of infants with trisomy 18.

A Rare Inherited 15q11.2-q13.1 Interstitial Duplication with Maternal Somatic Mosaicism, Renal Carcinoma, and Autism

Chromosome 15q11-q13.1 duplication is a common copy number variant associated with autism spectrum disorder (ASD). Most cases are de novo, maternal in origin and fully penetrant for ASD. Here, we describe a unique family with an interstitial 15q11.2-q13.1 maternal duplication and the presence of somatic mosaicism in the mother. She is typically functioning, but formal autism testing showed mild ASD. She had several congenital anomalies, and she is the first 15q Duplication case reported in the literature to develop unilateral renal carcinoma. Her two affected children share some of these clinical characteristics, and have severe ASD. Several tissues in the mother, including blood, skin, a kidney tumor, and normal kidney margin tissues were studied for the presence of the 15q11-q13.1 duplication. We show the mother has somatic mosaicism for the duplication in several tissues to varying degrees. A growth competition assay in two types of stem cells from duplication 15q individuals was also performed. Our results suggest that the presence of this interstitial duplication 15q chromosome may confer a previously unknown growth advantage in this particular individual, but not in the general interstitial duplication 15q population.

High Incidence of Noonan Syndrome Features Including Short Stature and Pulmonic Stenosis in Patients carrying NF1 Missense Mutations Affecting p.Arg1809: Genotype-Phenotype Correlation

Neurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders, affecting 1:3,000 worldwide. Identification of genotype–phenotype correlations is challenging because of the wide range clinical variability, the progressive nature of the disorder, and extreme diversity of the mutational spectrum. We report 136 individuals with a distinct phenotype carrying one of five different NF1 missense mutations affecting p.Arg1809. Patients presented with multiple café‐au‐lait macules (CALM) with or without freckling and Lisch nodules, but no externally visible plexiform neurofibromas or clear cutaneous neurofibromas were found. About 25% of the individuals had Noonan‐like features. Pulmonic stenosis and short stature were significantly more prevalent compared with classic cohorts (P < 0.0001). Developmental delays and/or learning disabilities were reported in over 50% of patients. Melanocytes cultured from a CALM in a segmental NF1‐patient showed two different somatic NF1 mutations, p.Arg1809Cys and a multi‐exon deletion, providing genetic evidence that p.Arg1809Cys is a loss‐of‐function mutation in the melanocytes and causes a pigmentary phenotype. Constitutional missense mutations at p.Arg1809 affect 1.23% of unrelated NF1 probands in the UAB cohort, therefore this specific NF1 genotype–phenotype correlation will affect counseling and management of a significant number of patients.

The interstitial duplication 15q11.2-q13 syndrome includes autism, mild facial anomalies and a characteristic EEG signature

Chromosomal copy number variants (CNV) are the most common genetic lesion found in autism. Many autism-associated CNVs are duplications of chromosome 15q. Although most cases of interstitial (int) dup(15) that present clinically are de novo and maternally derived or inherited, both pathogenic and unaffected paternal duplications of 15q have been identified. We performed a phenotype/genotype analysis of individuals with interstitial 15q duplications to broaden our understanding of the 15q syndrome and investigate the contribution of 15q duplication to increased autism risk. All subjects were recruited solely on the basis of interstitial duplication 15q11.2-q13 status. Comparative array genome hybridization was used to determine the duplication size and boundaries while the methylation status of the maternally methylated small nuclear ribonucleoprotein polypeptide N gene was used to determine the parent of origin of the duplication. We determined the duplication size and parental origin for 14 int dup(15) subjects: 10 maternal and 4 paternal cases. The majority of int dup(15) cases recruited were maternal in origin, most likely due to our finding that maternal duplication was coincident with autism spectrum disorder. The size of the duplication did not correlate with the severity of the phenotype as established by Autism Diagnostic Observation Scale calibrated severity score. We identified phenotypes not comprehensively described before in this cohort including mild facial dysmorphism, sleep problems and an unusual electroencephalogram variant. Our results are consistent with the hypothesis that the maternally expressed ubiquitin protein ligase E3A gene is primarily responsible for the autism phenotype in int dup(15) since all maternal cases tested presented on the autism spectrum.

Goltz syndrome: report of two severe cases

Goltz syndrome is a rare, X-linked dominant congenital disorder with abnormalities in derivatives of each of the three embryonic germ layers. Its clinical phenotype varies widely, ranging from isolated skin defects to absence of limbs and/or organs. The rarity and wide range of presentation contribute to delayed or missed diagnosis.

Treatment of Diffuse Basal Cell Carcinomas and Basaloid Follicular Hamartomas in Nevoid Basal Cell Carcinoma Syndrome by Wide-Area 5-Aminolevulinic Acid Photodynamic Therapy

OBJECTIVE

To report the use of wide-area 5-aminolevulinic acid photodynamic therapy to treat numerous basal cell carcinomas (BCCs) and basaloid follicular hamartomas (BFHs).

DESIGN

Report of cases.

SETTING

Roswell Park Cancer Institute. Patients Three children with BCCs and BFHs involving 12% to 25% of their body surface areas. Interventions Twenty percent 5-aminolevulinic acid was applied to up to 22% of the body surface for 24 hours under occlusion. A dye laser and a lamp illuminated fields up to 7 cm and 16 cm in diameter, respectively; up to 36 fields were treated per session.

MAIN OUTCOME MEASURES

Morbidity, patient response, and light dose-photodynamic therapy response relationship and durability.

RESULTS

Morbidity was minimal, with selective phototoxicity and rapid healing. After 4 to 7 sessions, with individual areas receiving 1 to 3 treatments, the patients had 85% to 98% overall clearance and excellent cosmetic outcomes without scarring. For laser treatments, a sigmoidal light dose-response relationship predicted more than 85% initial response rates for light doses 150 J/cm(2) or more. Responses were durable up to 6 years. Conclusion 5-Aminolevulinic acid photodynamic therapy is safe, well tolerated, and effective for extensive areas of diffuse BCCs and BFHs and appears to be the treatment of choice in children.

Prospective evaluation of the brain in asymptomatic children with neurofibromatosis type 1: relationship of macrocephaly to T1 relaxation changes and structural brain abnormalities

BACKGROUND AND PURPOSE

Mutation of the neurofibromatosis type 1 (NF-1) gene may be associated with abnormal growth control in the brain. Because macrocephaly could be a sign of abnormal brain development and because 30% to 50% of children with NF-1 display macrocephaly in the absence of hydrocephalus, we sought to determine the relationship between macrocephaly and other brain abnormalities in young subjects with NF-1. These subjects were free of brain tumor, epilepsy, or other obvious neurologic problems.

METHODS

We prospectively screened 18 neurologically asymptomatic subjects with NF-1, ages 6 to 16 years, using clinical measures, psychometric testing, conventional MR imaging, and quantitative MR imaging to measure T1.

RESULTS

Cranial circumference was 2 or more SDs above the age norm in seven (39%) of 18 subjects, a frequency of macrocephaly 17-fold higher than normal. Conventional MR imaging showed abnormalities in all 18 children, although there were more extensive abnormalities in subjects with macrocephaly. Macrocephaly in NF-1 was associated with enlargement of multiple brain structures, and brain T1 in macrocephalic subjects was reduced with respect to controls in the genu, frontal white matter, caudate, putamen, thalamus, and cortex. In normocephalic subjects, T1 was reduced only in the genu and splenium. Volumetric analysis showed that macrocephaly was associated specifically with enlargement of white matter volume.

CONCLUSION

Neurologically asymptomatic children with NF-1 showed macrocephaly, cognitive deficit, enlarged brain structures, and abnormally low brain T1. Macrocephaly in children with NF-1 may be associated with characteristic alterations in brain development, marked by more widespread and significant changes in T1, greater enlargement of midline structures, and greater volume of white matter.

Long-term survival in Patau syndrome

A female patient with an extra chromosome 13 (Patau syndrome) is described. There are only five previous reports of patients with trisomy 13 who have survived past the first decade. It is concluded that non-lethal congenital anomalies and aggressive medical care play an important role in the survival of patients with trisomy 13.

Cardiovascular malformations and other cardiovascular abnormalities in neurofibromatosis 1

Although it is well recognized that a peripheral vasculopathy may occur in patients with neurofibromatosis 1 (NF1), it is unclear whether cardiovascular abnormalities are more common. We reviewed the frequency of cardiovascular abnormalities, in particular, cardiovascular malformations (CVMs), among 2322 patients with definite NF1 in the National Neurofibromatosis Foundation International Database from 1991-98. Cardiovascular malformations were reported in 54/2322 (2.3%) of the NF1 patients, only 4 of whom had Watson syndrome or NF1-Noonan syndrome. There was a predominance of Class II "flow" defects [Clark, 1995: Moss and Adams' Heart Disease in Infants, Children, and Adolescents Including the Fetus and Young Adult. p 60-70] (43/54, 80%) among the NF1 patients with CVMs. Pulmonic stenosis, that was present in 25 NF1 patients, and aortic coarctation, that occurred in 5, constitute much larger proportions of all CVMs than expected. Of interest was the paucity of Class I conotruncal defects (2 patients with tetralogy of Fallot), and the absence of atrioventricular canal, anomalous pulmonary venous return, complex single ventricle and laterality defects. Besides the 54 patients with CVMs, there were 27 patients with other cardiac abnormalities (16 with murmur, 5 with mitral valve prolapse, 1 with intracardiac tumor, and 5 with electrocardiogram abnormalities). No patient in this study had hypertrophic cardiomyopathy. There were 16 patients who had a peripheral vascular abnormality without an intracardiac CVM, plus an additional 4 patients among those with a CVM who also had a peripheral vascular abnormality.

Neonatal progeroid (Wiedemann-Rautenstrauch) syndrome: report of five new cases and review

The neonatal progeroid syndrome (NPS), or Wiedemann-Rautenstrauch, is a rare autosomal recessive disorder comprised of generalized lipoatrophy except for fat pads in the suprabuttock areas, hypotrichosis of the scalp hair, eyebrows, and eyelashes, relative macrocephaly, triangular face, natal teeth, and micrognathia. We report on 5 new patients who demonstrate phenotypic variability and who represent the single largest series of NPS reported to date. Two of the patients are from an African-American kindred, an ethnic occurrence not reported previously. The fact that there are 2 pairs of sibs among the 5 patients further supports that NPS is an autosomal recessive condition. This report also includes a review of the previously reported 16 patients and compares them with the 5 new patients. Abnormalities in endocrine and lipid metabolism were found in 3 of 5 patients. Skeletal findings in 2 of our patients demonstrated some new findings as well as the typical radiological abnormalities previously noted in NPS. It is apparent, based on the 21 cases, that mild to moderate mental retardation is common in NPS. Long term follow-up of patients with NPS should provide more information relative to their ultimate psychomotor development. NPS is usually lethal by 7 months; however, on rare occasions, patients have survived into the teens. Our 3 surviving patients range in age from 16-23 months. Variability in the phenotype of NPS is clear; however, the phenotype remains distinct enough to allow a secure diagnosis.

Descriptive analysis of tibial pseudarthrosis in patients with neurofibromatosis 1

Five percent of individuals with neurofibromatosis type 1 (NF1) present with congenital long bone pseudarthrosis (PA). In large series, 50-80% of patients with congenital long bone PA also have NF1. Very little information exists on the natural history and pathogenesis of PA in NF1. This report is a descriptive analysis of a large series of patients with NF1 and tibial bowing or PA. Study A is a case-control study using the National Neurofibromatosis Foundation International Database (NNFFID). Eighty-five patients with PA were compared to a control group from the same database. There was a statistically significant male predominance of NF1 cases with PA (54 males to 31 females), compared to controls (85 males to 87 females) (chi2 = 4.0, P = 0.046, using a two-tailed test with Yates' correction). There was no significant difference in the clinical presentation of NF1 manifestations in NF1 patients with PA than in NF1 patients without PA. Of the affected individuals with PA, there were 24 de novo cases and 21 familial cases (9 through maternal and 12 through paternal inheritance). Questions that could not be answered by Study A were addressed by a partially overlapping case-series report, Study B, in which data on 75 cases ascertained through questionnaires completed by NF center directors were collected. From Study B we determined that half of the patients who had a fracture sustained it before age 2, and approximately 16% of the pseudarthrosis patients had an amputation. Our data indicate a male predominance and no parent-of-origin effect. Male gender may be a susceptibility factor for pseudarthrosis in NF1.

Interpupillary distance in a normal black population

This report expands on a study by Pryor [Pryor HB. Objective measurement of interpupillary distance. Pediatrics 1969: 44: 973 977] that related normal values of inner canthal distance (ICD), outer canthal distance (OCD) and interpupillary distance (IPD) for Whites, Asians and Mexican Americans. To date, no similar values have been reported for Blacks. Utilizing a sample (n = 931: 485 males; 446 females) of black people (range, birth 24 years), OCD, ICD, and head circumference (HC) were measured and tabulated. We calculated mean IPD according to Pryor's formulation and report that the general mean OCD and ICD in our sample differed significantly from, and were consistently higher than, Pryor's reported measurements for White males and females at each age level (p < 0.001). However, ICD in our sample was significantly lower at birth in both sexes, appeared to increase at a more rapid rate relative to Whites during the first 3 months of life, and reached and maintained a higher value beyond the age of 3 months, with most age groups showing a significant difference in mean ICD measurements. At each age level, the mean IPD values in Whites and Blacks were significantly higher (p < 0.001). Based upon these findings, we suggest that interpupillary distance of Black children and adults be assessed according to the mean proportions for their race.

Infant with midline thoracoabdominal schisis and limb defects

An infant presented with multiple congenital anomalies including a midline thoracoabdominal defect, absence of the sternum, ectopia cordis, right diaphragmatic hernia, right anophthalmia, left microphthalmia, incomplete bilateral cleft lip, and various limb defects including ectrodactyly of the right hand and left foot, and phocomelia of the right lower extremity. The infant expired soon after birth. The radiological findings included absence of the sternum, 11 right-sided ribs, absence of the middle third of the right clavicle, opaque right hemithorax, hypoplastic right tibia, absent right fibula and foot, and ectrodactyly of the right hand and left foot. In addition, the autopsy revealed two distinct diaphragmatic defects, an anterior midline defect of the diaphragm beneath the ectopic heart, and a large Bochdalek hernia, with abdominal contents in the chest. Our case has overlapping features with conditions such as thoracoabdominal syndrome, pentalogy of Cantrell, and limb-body wall complex, but the concurrence of midline body wall defect and ectrodactyly has not been described previously.

Neurofibromatosis type 1 (NF1): a protein truncation assay yielding identification of mutations in 73% of patients

Neurofibromatosis type 1 (NF1) is caused by mutations in a tumour suppressor gene located on chromosome 17 (17q11.2). Disease causing mutations are dispersed throughout the gene, which spans 350 kilobases and includes 59 exons. A common consequence of NF1 mutations is introduction of a premature stop codon, and the majority of mutant genes encode truncated forms of neurofibromin. We used a protein truncation assay to screen for mutations in 15 NF1 patients and obtained positive results in 11 of them (73%). Sequencing of cDNA and genomic DNA yielded identification of 10 different mutations, including four splicing errors, three small deletions, two nonsense mutations, and one small insertion. Nine mutations were predicted to cause premature termination of translation, while one mutation caused in frame deletion as a result ofexon skipping. In one other case involving abnormal splicing, five different aberrantly spliced transcripts were detected. One germline nonsense mutation (R1306X, 3916C>T) corresponded to the same base change that occurs by mRNA editing in normal subjects. The second nonsense mutation (R2496X) was the sole germline mutation that has been previously described. The subjects studied represented typically affected NF1 patients and no correlations between genotype and phenotype were apparent. A high incidence of ocular hypertelorism was observed.

Alternative splicing of exons 29 and 30 in the neurofibromatosis type 1 gene

Alternative splicing of exons 29 and 30 of the human neurofibromatosis type 1 (NF1) gene was detected by reverse transcription/polymerase chain reaction (RT-PCR). Three different isoforms that omitted either one or both exons were identified (ex29-, ex30-, and ex29/30-). The alternatively spliced transcripts exhibited tissue-specific differences, with the ex30- variant apparent only in brain. All three isoforms altered the reading frame and introduced a stop codon in the adjacent downstream exon. Alternative splicing of this region of the NF1 gene also was detected in RNA from rats, although only the ex30- variant was observed. RNA from mice revealed only constitutive expression in this region of the NF1 gene. This study adds a new site of alternative processing to the complex expression of NF1.

Bony orbital morphology in neurofibromatosis type 1 (NF1)

We retrospectively compared patients with NF1 with and without optic pathway gliomas (OPG) to determine the incidence and range of orbital developmental abnormalities and compared the incidence of OPG in African-Americans and whites. From cranial MR scans, we manually measured 14 orbital dimensions, compared them to published standards of Waitzman et al, calculated orbital volumes, and determined the presence or absence of volumetric symmetry (delta v) (delta v < or = 3 cm3 was considered to be symmetrical). We compared the results of orbital configurational assessment between patients with (group I) and those without OPG (group II). The study population comprised 58 patients, 24 boys, 18 African-American, and one Hispanic. Median age at imaging was 7 years (range 0.5-25.5 years). Fifty-eight percent had conformational abnormalities, 16 of whom had more than one abnormality (28%), the most frequent being increased intertemporal distance (n=10), increased lateral orbital distance (n=8), increased medial wall length (n=6), and decreased medial wall length (n=6). The increased intertemporal and lateral orbital distances may contribute to the appearance of hypertelorism. Only two patients had sphenoid wing hypoplasia. We found a high incidence of orbital dimensional abnormalities in the total population but more often saw multiple abnormalities in patients with OPG. However, no pattern of configurational abnormality emerged. OPG is less frequent in African-Americans. Orbital volumetric disparity seems to be independent of the presence of OPG.

Simultaneous adrenocortical carcinoma and ganglioneuroblastoma in a child with Turner syndrome and germline p53 mutation

The predisposition to malignancy that is dominantly inherited in Li-Fraumeni syndrome is associated with germline mutations of the tumour suppressor gene p53. Although second malignant neoplasms have been described in children with p53 mutations, the synchronous occurrence of two embryologically different tumours in these children has not been reported. A 20 month old girl with failure to thrive and congenital heart defects was found to have unilateral adrenal masses which, at surgical removal, proved to be an adrenocortical carcinoma and a ganglioneuroblastoma. Further investigation showed a germline p53 mutation and Turner syndrome. It remains to be determined what effect the 45,X chromosomal complement may have on the expression of neoplasms seen in patients with p53 germline mutations.

Most Jacobsen syndrome deletion breakpoints occur distal to FRA11B

Recent studies have identified a (CCG)n repeat in the 5' untranslated region of the CBL2 protooncogene (11q23.3) and have demonstrated that expansion of this repeat causes expression of the folate-sensitive fragile site FRA11B. It has also been demonstrated that FRA11B is the site of breakage in some cases of Jacobsen syndrome (JS) involving terminal deletions of chromosome 11q. We report on 2 patients with JS and a 46,XX,del(11)(q23.3) karyotype. In both cases, microsatellite and fluorescence in situ hybridization analyses indicated that the deletion breakpoint was approximately 1.5-3 Mb telomeric to FRA11B. There was no evidence of expansion of the CBL2 (CCG)n repeat in the parents of either patient. The deleted chromosome was of paternal origin in both cases, although it was of maternal origin in the cases reported to be caused by FRA11B. These findings and those in previously reported patients suggest that the breakpoint for most 11q deletions in JS patients is telomeric to FRA11B, which raises the possibility that there may be other fragile sites in 11q23.3 in addition to FRA11B. These findings also support previous evidence that there may be a propensity for breakpoints to differ depending on the parental origin of the deleted chromosome.

Hair whorl as an indicator of a mediastinal plexiform neurofibroma

We report a boy with neurofibromatosis type 1 (NF-1) who had nonspecific respiratory symptoms and a mediastinal mass. In addition to multiple caté au lait macules and subcutaneous neurofibromas, he had a hair whorl over the spine at the level of a deep mediastinal mass demonstrated by CT scan and MR examination. Thoracoscopy and biopsy of the mass revealed a plexiform neurofibroma. The clinical sign of a hair whorl may assist the clinician in early recognition of a paraspinal plexiform neurofibroma.

Complications of the nevoid basal cell carcinoma syndrome: a case report

PURPOSE

We report that patients with nevoid basal cell carcinoma syndrome (Gorlin syndrome) are at risk for developing neoplasms, especially basal cell carcinomas and rarely medulloblastoma.

METHODS

A case report is presented of a 5-year-old child with medulloblastoma and multiple basal cell carcinomas who was diagnosed with nevoid basal cell carcinoma syndrome. Genetic analyses were performed on tumor DNA from the patient's medulloblastoma and basal cell carcinoma as well as germline DNA from the patient and unaffected family members.

RESULTS

After radiation therapy for medulloblastoma, the patient developed thousands of additional basal cell carcinomas. Analysis of tumor DNA revealed the characteristic defect of nevoid basal cell carcinoma syndrome, loss of heterozygosity at 9q22. Photodynamic therapy was successfully used to control the majority of her cutaneous tumors.

CONCLUSION

DNA analysis confirmed the presence of the distinctive genetic lesion of nevoid basal cell carcinoma syndrome in both medulloblastoma and basal cell carcinoma. Omitting or limiting radiation therapy for children with nevoid basal cell carcinoma syndrome and medulloblastoma should be considered.

Jacobsen syndrome: report of a patient with severe eye anomalies, growth hormone deficiency, and hypothyroidism associated with deletion 11 (q23q25) and review of 52 cases

We have evaluated a patient with Jacobsen syndrome. The patient presented with growth retardation, hypotonia, trigonocephaly, telecanthus, downward slanting palpebral fissures, bilateral inferior colobomas (of the iris, choroid, and retina), hydrocephalus, central nervous system (CNS) abnormalities, and an endocardial cushion defect, features commonly seen in Jacobsen syndrome. Endocrine evaluation showed growth hormone deficiency and central hypothyroidism. Chromosome analysis showed a 46,XX,del(11)(q23q25) de novo karyotype. Cytogenetically, the deletion appeared to include most of bands 11q23 and q24 and a portion of q25. Using chromosome specific paint probe, a combination of chromosome 11 centromere, telomere, and region specific cosmid probes from 11q14.1-14.3, 11q23.3, and 11q24.1, we have localised the deletion breakpoint to q24.1. Phenotype-karyotype correlation of patients with Jacobsen syndrome and specific deletions of chromosome 11q has enabled us to suggest that the critical region for this syndrome lies in close proximity to cytogenetic band 11q24. Although growth retardation is a consistent finding in 11q deletion syndrome, the presence of hypothalamic-pituitary hormone deficiency has not been reported previously.

A jumping Robertsonian translocation: a molecular and cytogenetic study

We report a patient with mosaicism for two different Robertsonian translocations, both involving chromosome 21. She carries an unbalanced cell line with an i(21q) and a balanced cell line with a rob(21q22q). She is phenotypically normal but has two children who inherited the i(21q) and have Down syndrome. We demonstrate that both abnormal chromosomes are dicentric and that the proband's 21/21 rearrangement is an isochromosome formed from a maternally derived chromosome 21. We propose a model in which the i(21q) is the progenitor rearrangement in the proband, which subsequently participated in a nonreciprocal rearrangement characteristic of a jumping translocation. In addition, we review other cases of constitutional mosaicism involving jumping translocations.

Gorlin syndrome associated with midline nasal dermoid cyst

Gorlin syndrome is an autosomal dominant multisystem disorder characterised by multiple basal cell naevi, cysts of the jaw, pits of the palms and soles, skeletal anomalies, and various other defects. Patients with Gorlin syndrome have a predisposition to basal cell carcinomas and other neoplasms. This is the first report to describe the coexistence of Gorlin syndrome and a nasal dermoid cyst. A 4 year old girl was diagnosed with medulloblastoma and treated with surgery and radiation therapy. A genetic evaluation was sought because of the brain tumour, multiple small naevi localised mostly on the upper torso, and rib abnormalities. Biopsies of several naevi showed naevoid basal cell carcinoma. Past medical history was significant for a midline nasal punctum noted at birth. The significance of this finding was unrecognised until the dermoid cyst enlarged, just before the diagnosis of her brain tumour. A common tissue of origin exists between basal cell naevi, cysts of the jaw, and dermoid cysts. We propose that the association of these two rare conditions in one patient is not a chance occurrence.

Hypertrichosis, pigmentary retinopathy, and facial anomalies: a new syndrome?

We report on a 22-month-old male with congenital hypertrichosis of the face, arms, legs, shoulders, back, and buttocks, abnormal facial appearance, dolichocephaly, and pigmentary retinopathy. Symmetrical hyperpigmentation is present on the sideburn areas of his face, and hyperpigmented streaks are seen on arms and legs. Biopsy of the hyperpigmented' skin showed many separate bundles of smooth muscles in the dermis. No relative had hypertrichosis or other birth defects. To our knowledge, the syndrome of facial anomalies, pigmentary retinopathy, and congenital hypertrichosis has not been reported previously.

Rickets secondary to phosphate depletion. A sequela of antacid use in infancy

Two infants presented with growth failure and were found to have generalized osteomalacia (rickets) due to phosphate depletion from prolonged administration of an aluminum-containing antacid given for the symptoms of colic. One of the infants developed bilateral proptosis due to craniosynostosis related to the underlying metabolic bone disease. The chronic use of aluminum-containing antacids in infants has potential risk for the growing skeleton and is not innocuous. Therefore, antacid therapy should be used in low doses and very cautiously, with routine monitoring of serum calcium and phosphorus in children taking medications which reduce gastrointestinal phosphate absorption.

Mutations in the conserved domain of SRY are uncommon in XY gonadal dysgenesis

In order to evaluate the role of SRY in the determination of the testis, we sequenced the conserved domain of the SRY gene in 8 patients with 46,XY gonadal dysgenesis and 3 patients with related disorders, and compared our data with those obtained in 6 other similar studies. In our study, a 609-bp fragment of SRY was amplified by the polymerase chain reaction and the internal conserved motif was sequenced. SRY sequences did not differ from those in normal males in any of our patients. Overall, 5 de novo mutations have been identified among 56 patients with sporadic XY gonadal dysgenesis (8.9%), and 2 de novo mutations have been identified among 18 patients with related conditions (11%). The unexpectedly low frequency of mutations within the SRY conserved domain in these patients could be caused by undetected Y-linked mutations outside the conserved domain in regions that control transcription during development (e.g., promoter/enhancer regions) or to downstream mutations in other sex-determining genes that need not map to the Y.

Hallermann-Streiff syndrome with hypopituitarism contributing to growth failure

A 35-month-old black boy with Hallermann-Streiff syndrome (HSS) was evaluated for anterior hypopituitarism when he presented with ketotic hypoglycemia, microgenitalia, and short stature. Endocrine evaluation showed a low T4 and TSH levels, suggesting hypothalamic hypothyroidism; this was confirmed by TRH stimulation. Metyrapone test confirmed ACTH deficiency as a contributing factor to the ketotic hypoglycemia. A superagonist GnRH test suggested hypothalamic GnRH deficiency. Growth hormone provocative testing conclusively demonstrated complete growth hormone deficiency. MRI investigation of the brain suggested hypopituitarism. Although facial findings were not completely classical of the HSS, we suggest these may be somewhat altered due to his racial back-ground. We recommend endocrine evaluation of HSS patients with manifestations suggesting hypopituitarism since treatment of this condition will improve the quality of life of these patients.

Adjacent-2 disjunction of a maternal t(9;22) leading to duplication 9pter----q22 and deficiency of 22pter----q11.2

The proposita presented at birth with multiple congenital anomalies including craniofacial anomalies, bilateral cleft lip and palate, abnormalities of the urogenital system, talipes equinovarus, and the DiGeorge sequence. Cytogenetic investigation showed a 46,XX,-22,+der(9)t(9;22)(q22;q11.2) karyotype. The mother, maternal uncle, and maternal grandmother of the infant are carriers of a reciprocal balanced translocation involving chromosomes 9 and 22 at regions q22 and q11.2, respectively. The unbalanced karyotype seen in the proposita arose due to an adjacent-2 disjunction of the quadrivalent in the mother. Prenatal diagnosis of the second pregnancy of this woman showed a similar karyotype. Review of the literature shows that adjacent-2 disjunction may occur preferentially when certain chromosomes are involved in translocations.

Partial duplication of the long arm of chromosome 6: a clinically recognisable syndrome

Reciprocal translocations involving the short arm of acrocentric chromosomes can segregate to produce partial duplications without associated deletions. We present a case of an infant with a 46,XY,-15,+der(15),T(6;15)(q23;p12)pat chromosome complement. The infant had multiple congenital abnormalities including cranial anomalies, facial dysmorphism, anterior webbing of the neck, cardiac anomalies, and joint contractures. From a comparison of the infant's phenotype with 20 other patients with a similar duplication, it is evident that partial duplication of the long arm of chromosome 6 is a clinically diagnosable syndrome.