|Year : 2021 | Volume
| Issue : 3 | Page : 190-192
Desaturation during feeding in a term neonate due to 20p duplication syndrome
Kadirvel Karthikeyan1, Chandra Kumar Natarajan2, Sumathisri Ramachandran1
1 Department of Pediatrics, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India
2 Department of Neonatology, Kanchi Kamakoti CHILDS Trust Hospital, Chennai, Tamil Nadu, India
|Date of Submission||07-Apr-2021|
|Date of Decision||01-Aug-2021|
|Date of Acceptance||09-Aug-2021|
|Date of Web Publication||31-Aug-2021|
Dr. Kadirvel Karthikeyan
Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry
Source of Support: None, Conflict of Interest: None
Background: Feeding problems are common in preterm neonates of which desaturation during direct feeding is a known entity. However, term newborns have acceptable range of fall in saturation while feeding directly. Here, we report a term newborn with dysmorphic features had desaturation during feeding. Clinical Description: A male baby born to second-degree consanguineous parents at term who was managed for transient tachypnea of newborn had fall in saturation beyond acceptable range during feeding. He had low set ears, high-arched palate, thin upper lip, clinodactyly, and anal tag. Management: The baby was subjected for thorough exploration of respiratory/gastrointestinal/neurological systems which did not reveal attributable findings. Clinical exome sequencing revealed 20p duplication. He was started on orogastric feeding and could be gradually changed to direct feeding at 4 months of age. Conclusions: This report may improve the understanding toward approach to feeding problems in term neonates and also about phenotypic features of 20 p duplication which is less reported.
Keywords: 20p duplication, clinical exome sequencing, desaturation during feeding, dysmorphism, term neonate
|How to cite this article:|
Karthikeyan K, Natarajan CK, Ramachandran S. Desaturation during feeding in a term neonate due to 20p duplication syndrome. Indian Pediatr Case Rep 2021;1:190-2
|How to cite this URL:|
Karthikeyan K, Natarajan CK, Ramachandran S. Desaturation during feeding in a term neonate due to 20p duplication syndrome. Indian Pediatr Case Rep [serial online] 2021 [cited 2021 Sep 26];1:190-2. Available from: http://www.ipcares.org/text.asp?2021/1/3/190/325076
A misconception that is sometimes encountered in health-care providers is that there may be a fall in oxygen saturation in newborns while they are breastfeeding. This incorrect extrapolation probably arose from the results of studies in preterm babies. However, there is no concrete evidence to authenticate a similar significant fall in saturation in healthy term neonates. In healthy term infants, there may be a transient drop in oxygenation in the immediate postfeed period,, but it should always be within the acceptable levels of oxygen saturation, i.e. >94%.
This case report is regarding a term neonate with dysmorphic features who was evaluated for a significant drop in saturation beyond acceptable limits during feeding and detected to have underlying genetic defect (20p duplication) that has been reported to have this kind of clinical presentation. The objective of this report is to contribute to the understanding and clinical workup of infants with feeding difficulties and also to expand the clinical phenotype of 20p duplication syndrome, as features of these children are underreported.
| Clinical Description|| |
A term baby boy, born in an extramural health facility, via a cesarean section (indication being a previous cesarean section) was transferred to the neonatal intensive care unit of our institute on the 1st day of life for respiratory distress since birth. The APGAR scores were 8 and 9 at 1 and 5 min, respectively. There was no sepsis setting. He weighed 2600 g at birth. The mother was 34 years old with an uneventful antenatal period. He was born to second-degree consanguineous parents with no significant family history. He had an elder sister with normal development.
The vitals at admission were respiratory rate of 66/min with lower intercostal retractions, and saturation maintained at 97% only with oxygen via prongs. Continuous positive airway pressure was started. Anthropometry (weight 2600 g, length 49 cm, and head circumference 33.5 cm) was within normal limits. It was noted that the newborn had multiple minor congenital anomalies [Table 1] and [Figure 1], [Figure 2]. The septic workup and chest roentgenogram were normal. A two-dimensional echocardiogram showed a 2-mm defect in the atrial septum. The respiratory distress gradually improved, and we were able to wean him off oxygen support by 40 h of life. Given the natural course of illness and investigation profile, a diagnosis of transient tachypnea of the newborn was kept. Initially, the baby had been given orogastric (OG) tube feeding. When direct breastfeeding was started, a dramatic drop in SpO2-45% with associated cyanosis was observed. Perfusion at that point of time was normal, the baby was normothermic, the form of the plethysmographic wave was normal and the placement of probe was correct. The hypoxia got immediately corrected on starting free-flow oxygen by nasal prongs. This event occurred on several occasions, hence we reverted to OG tube feedings.
|Figure 2: Left foot showing uneven toe length and overriding of the second toe over the great toe|
Click here to view
| Management and Outcome|| |
The baby was assessed for the presence of other concealed anomalies. We started with evaluating the upper airways for causes of obstruction. No difficulty was observed in passing a 6 French (6 Fr) suction catheter through both nares. The upper airway computed tomography (CT) scan followed by flexible nasal endoscopy confirmed partial left choanal atresia with a deviated nasal septum. Evaluation of the lower airways was done by fiber-optic bronchoscopy which revealed tracheomalacia. A CT angiogram showed a bovine type of aortic arch (left common carotid artery merges with the origin of the brachiocephalic artery, rather than arising directly from the aortic arch as a separate branch). Normal gastrointestinal (GI) tract anatomy was found on an upper GI barium contrast study, while a videofluoroscopic swallow study demonstrated efficient oral phase function with no evidence of supraglottic penetration or aspiration. Cerebral dysgenesis was ruled out by magnetic resonance imaging of the brain. However, none of these findings were a plausible explanation for the desaturation that was occurring during feeding. Ultrasonogram of the abdomen was normal. Thus, no major congenital anomaly was identified. The synthesis of all clinical data did not fit into any syndrome known to any of the treating clinicians. Neither did an online search help to establish diagnosis.
Genetic testing was simultaneously planned as per protocol of evaluation of children with multiple congenital anomalies. Clinical exome sequencing reported a likely pathogenic copy number variant with a phenotypic description; Chr 20: G.(?_407606)_(20052779_?) dup; autosomal dominant inheritance. High-resolution karyotyping confirmed additional chromosome material attached to terminal band of long arm of chromosome 20. The final diagnosis was 20p duplication syndrome. The parents were given genetic counseling regarding the nature of the genetic condition, genotypic-phenotypic correlation, and prognosis in terms of the individual anomalies and possibility of developmental delay. OG tube feedings were continued postdischarge after ensuring that the mother had become competent to administer them without supervision. The baby was kept under close follow-up, with periodic monitoring of nutritional status and development. Trials of expressed breast milk (EBM) under saturation monitoring were also done during these visits. The baby tolerated EBM by cup and spoon feeding for the first time without desaturation at 4 months of age. This was continued, but the weight gain was not satisfactory. Upon introduction of complementary feeding, the weight gain started to increase significantly. Developmental delay was identified at 6 months (motor and mental quotient 65 and 55, respectively), for which early intervention was started.
| Discussion|| |
Our workup followed three pathways: first, looking for the cause of desaturation while feeding; second, defining the clinical phenotype; and third, looking for an underlying genetic etiology of the multiple congenital anomalies. It is very important to do a complete exploration of the upper respiratory and GI anatomy when looking for causes of feeding-related difficulties, as was done in the workup of this case. Numerical and structural abnormalities involving chromosome 20 are relatively rare. Till date, less than fifty cases have been reported. Chromosome 20p duplication is rarer than deletions. In 20p duplication, extra material from the short arm of chromosome 20 is placed on the body of the same chromosome. Duplications of the long arm can also occur rarely.
Infants with duplication exhibit wide variability in the clinical phenotype depending on the size of the duplicated segment. A literature search of previously reported cases revealed the following clinical phenotype;,, typical facies (round face with prominent cheeks, coarse and usually straight hair, and upward slanting of eyes), developmental delay, learning difficulty, and difficulty in coordinating movement, speech delay, and malformed or fused vertebrae. Fused or irregularly shaped vertebrae have been frequently shown spinal abnormalities and develop kyphosis. Minor genital anomalies are relatively common, as are congenital cardiac septal defects. Unusual findings are short nose with large nostrils, hypertelorism, occipital flattening, epicanthic folds, strabismus, and congenital cardiac defects.,, Vision and hearing are generally unaffected, although some children display strabismus or astigmatism.
Although growth is usually unaffected, there are reports of children exhibiting height >97th centile and macrocephaly. Balestrazzi et al. suggested that if prepubertal macroorchidism is identified in the presence of intellectual disability, trisomy 20p should be considered as a differential diagnosis. Developmental delay and learning difficulties are common, but the severity is variable. Children with large duplication including parts of 20q in addition to the whole of 20p may have more severe cognitive impairment. Early assessment and intervention may help children achieve their expected potential. A literature search suggests that infants with 20p duplication who have no congenital anomalies of the major organ systems can have normal growth and development with healthy survival into adulthood.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient's mother has given his consent for images and other clinical information to be reported in the journal. The patient's mother understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Shivpuri CR, Martin RJ, Carlo WA, et al
. Decreased ventilation in preterm infants during oral feeding. J Pediatr 1983;103:285-9.
Mathew OP, Clark ML, Pronske ML, et al
. Breathing pattern and ventilation during oral feeding in term newborn infants. J Pediatr 1985;106:810-3.
Lu YC, Wang CC, Lee CM, et al
. Reevaluating reference ranges of oxygen saturation for healthy full-term neonates using pulse oximetry. Pediatr Neonatol 2014;55:459-65.
Della-Rosa VA, Vianna-Morgante AV. Partial duplication of chromosome 20(pter → q12). Genet Mol Biol 2000;23:545-47.
Sidwell RU, Pinson MP, Gibbons B, et al
. Pure trisomy 20p resulting from isochromosome formation and whole arm translocation. J Med Genet 2000;37:454-8.
Grammatico P, Cupilari F, Di Rosa C, et al
. 20 p duplication as a result of parental translocation: Familial case report and a contribution to the clinical delineation of the syndrome. Clin Genet 1992;41:285-9.
Bartolini L, Sartori S, Lenzini E, et al
. De novo
trisomy 20p characterized by array comparative genomic hybridization: Report of a novel case and review of the literature. Gene 2013;524:368-72.
Trachoo O, Assanatham M, Jinawath N, et al
. Chromosome 20p inverted duplication deletion identified in a Thai female adult with mental retardation, obesity, chronic kidney disease and characteristic facial features. Eur J Med Genet 2013;56:319-24.
Fagan K, Soubjaki V, Donald P, et al
. Fine molecular mapping of the 4p16.3 aneuploidy syndromes in four translocation families. J Med Genet 2000;37:449-51.
Wieczorek D, Bartsch O, Gillessen-Kaesbach G. Distal monosomy 18p/distal trisomy 20p--a recognizable facial phenotype? Am J Med Genet A 2003;120A:429-33.
Balestrazzi P, Virdis R, Frassi C, et al
. “De Novo
” trisomy 20p with macroorchidism in a prepuberal boy. Ann Genet 1984;27:58-9.13.
[Figure 1], [Figure 2]