The clinical geneticist and the evaluation of failure to thrive versus failure to feed

Etiologies of Poor Weight Gain and Ultimate Diagnosis in Children Admitted for Growth Faltering

BACKGROUND AND OBJECTIVES

Growth faltering (GF) (previously failure to thrive) is a common reason for hospital admission, but there is little data on whether diagnoses made during initial admission remain accurate in follow-up. We sought to characterize infants admitted for isolated GF and identify diagnoses at discharge and ultimate diagnoses determined over 2 years of follow-up, to determine how diagnoses changed. We also sought to identify patient factors on admission associated with ultimate diagnosis.

METHODS

We conducted a retrospective study of children aged 2 weeks to 2 years with index admissions for GF from 2013 to 2017. We reviewed clinical data and documentation to determine discharge and ultimate diagnosis, and identify factors associated with ultimate diagnosis.

RESULTS

Of 497 patients, 292 (59%) had insufficient intake, 103 (20%) had organic disease including 36 genetic disorders, 52 (11%) had mechanical feeding difficulties, and 50 (10%) had mixed or unknown diagnoses 2 years after admission. Over 90% of cases of insufficient intake were diagnosed during admission. Sixty-five percent of organic diseases, and only 39% of genetic disorders, were diagnosed during admission. Patient factors associated with genetic disorders included previous NICU stay, low birth weight, dysphagia, hypotonia, and dysmorphisms.

CONCLUSIONS

Insufficient intake remains the most common diagnosis, and this diagnosis was accurately made during admission. Organic disease, especially genetic disease, was often not diagnosed during admission. Better tools are needed to identify patients with organic disease. We identified patient factors on admission associated with ultimate diagnosis, which could be used to prioritize evaluation and expedite follow-up.

The past, present, and future of child growth monitoring: A review and primer for clinical genetics

Child growth measurements are critical vital signs to track, with every individual child growth curve potentially revealing a story about a child's health and well-being. Simply put, every baby born requires basic building blocks to grow and thrive: proper nutrition, love and care, and medical health. To ensure that every child who is missing one of these vital aspects is identified, growth is traditionally measured at birth and each well-child visit. While the blue and pink growth curves appear omnipresent in pediatric clinics, it is surprising to realize that their use only became standard of care in 1977 when the National Center for Health Statistics (NCHS) adopted the growth curve as a clinical tool for health. Behind this practice lies a socioeconomically, culturally, and politically complex interplay of individuals and institutions around the world. In this review, we highlight the often forgotten past, current state of practice, and future potential of this powerful clinical tool: the growth reference chart, with a particular focus on clinical genetics practice. The goal of this article is to understand ongoing work in the field of anthropometry (the scientific study of human measurements) and its direct impact on modern pediatric and genetic patient care.

Creatine Transporter Deficiency Presenting as Failure to Thrive: A Case Report of a Novel SLC6A8 Variant Causing a Treatable but Likely Underdiagnosed Genetic Disorder

Cerebral creatine deficiency syndromes (CCDS) are a rare group of inherited metabolic disorders (IMDs) that often present with nonspecific findings including global developmental delay (GDD), intellectual disability (ID), seizures, hypotonia, and behavioral differences. Creatine transporter (CRTR) deficiency is the most common CCDS, exhibiting X-linked inheritance and an estimated prevalence as high as 2.6% in individuals with neurodevelopmental disorders. Here, we present a 20-month-old boy with worsening failure to thrive (FTT) and GDD admitted for evaluation. He was found to have persistently low serum creatinine levels and a family history notable for a mother with learning disabilities and a maternal male cousin with GDD. Urine analyses revealed a marked elevation of creatine and elevated creatine:creatinine ratio suggestive of CRTR deficiency. Molecular genetic testing of SLC6A8 identified a maternally inherited hemizygous variant and brain magnetic resonance spectroscopy (MRS) showed diffusely diminished creatine peaks, further supporting the diagnosis of CRTR deficiency. The proband was started on creatine, arginine, and glycine supplementation and has demonstrated improved development. This case highlights that CRTR deficiency should be considered in all patients presenting with FTT and abnormal neurodevelopmental features, particularly if creatinine levels are low on serum chemistry studies. The nonspecific presentation of this condition in males and females likely has resulted in CRTR deficiency being underdiagnosed. There are existing therapies for individuals affected with CRTR deficiency and other CCDS, highlighting the importance of early diagnosis and intervention for affected individuals.

Deficiency of acyl-CoA synthetase 5 is associated with a severe and treatable failure to thrive of neonatal onset

Failure to thrive (FTT) causes significant morbidity, often without clear etiologies. Six individuals of a large consanguineous family presented in the neonatal period with recurrent vomiting and diarrhea, leading to severe FTT. Standard diagnostic work up did not ascertain an etiology. Autozygosity mapping and whole exome sequencing identified homozygosity for a novel genetic variant of the long chain fatty acyl-CoA synthetase 5 (ACSL5) shared among the affected individuals (NM_203379.1:c.1358C>A:p.(Thr453Lys)). Autosomal recessive genotype-phenotype segregation was confirmed by Sanger sequencing. Functional in vitro analysis of the ACSL5 variant by immunofluorescence, western blotting and enzyme assay suggested that Thr453Lys is a loss-of-function mutation without any remaining activity. ACSL5 belongs to an essential enzyme family required for lipid metabolism and is known to contribute the major activity in the mouse intestine. Based on the function of ACSL5 in intestinal long chain fatty acid metabolism and the gastroenterological symptoms, affected individuals were treated with total parenteral nutrition or medium-chain triglyceride-based formula restricted in long-chain triglycerides. The patients responded well and follow up suggests that treatment is only required during early life.

Malnutrition and Medical Neglect

Anomalies found during the assessment of nutrition in children are common in pediatric practice, yet few articles address the intersection between malnutrition and medical neglect. The diagnosis of medical neglect requires several components including a) harm, or risk of harm due to lack of recommended health care, b) recommended care provides benefit significantly greater than potential risk, c) caregiver understands the medical recommendations; and d) has access to the recommended care, but fails to utilize it. Through the application of this definition to cases of malnutrition, considerations for diagnosing medical neglect when presented with malnutrition are reviewed. Cases include children with special healthcare needs, children exposed to selective diets, previously well children with severe malnutrition, and treatment-resistant failure to thrive. Obesity is a state of malnutrition, which may also involve neglect; in this instance, the "neglect" involves failure to supervise nutritional intake necessary for optimal functioning. Because many cases involve interactions with medical providers, the subsequent failure to follow medical advice regarding obesity management may also be considered medical neglect. This article reviews the relationship between medical neglect, nutritional deprivation, and over-nutrition to explore when a diagnosis of medical neglect may be applicable.

A case of diencephalic syndrome presenting with isolated lipodystrophy

Diencephalic syndrome is a disorder characterized by severe emaciation during childhood. The rarity of the disorder coupled with nonspecific symptomology means that there is often a protracted diagnostic journey. Here, we report a child who was referred to a clinical genetics service for investigation of lipodystrophy and failure to thrive. A broad range of genetic differential diagnoses were considered and investigated before a mass lesion was identified in the hypothalamus, confirming diencephalic syndrome. In the context of this case, we consider the relevant differentials and appropriate workup of a child with lipodystrophy presenting to a genetics service. This report also highlights the importance of considering diencephalic syndrome in cases such as this.

Behavioral Outbursts in a Child with a Deletion Syndrome, Generalized Epilepsy, Global Developmental Delay, and Failure to Thrive

A 7-year-old girl with 20q13.33 deletion and a history of generalized convulsive epilepsy presented to the Developmental and Behavioral Pediatrics Clinic due to concerns about her behavioral outbursts in the context of overall delayed development. Evaluation by the Developmental and Behavioral and Gastroenterology teams revealed failure to thrive (FTT) as the primary cause of the behavioral outbursts and developed a high-calorie, high-fat, high-protein nutritional counseling plan. Children who have FTT and a genetic disorder are often thought to not thrive because of their underlying genetic disorder; however, feeding skills and nutritional intake need to be thoroughly investigated before determining an etiology for FTT. Motoric, communicative, and developmental skills in children with genetic disorders may impede appropriate feeding mechanisms, inducing or exaggerating FTT in these children with developmental disabilities due to genetic etiologies. [Pediatr Ann. 2018;47(3):e130-e134.].

[Child abuse from a pediatric perspective]

CLINICAL ISSUE

Child abuse is the physical, sexual or emotional maltreatment, or neglect of a child or children. Child maltreatment is defined as any act or series of acts of commission or omission by a parent or other caregiver that results in harm, potential for harm, or threat of harm to a child. Child abuse can occur in a child's home, or in the organizations, schools or communities the child interacts with. There are four major categories of child abuse: neglect, physical abuse, psychological or emotional abuse, and sexual abuse.

DIAGNOSTIC WORK-UP

In child abuse, establishing an early diagnosis is essential. Apart from taking a detailed history and performing a meticulous physical examination, including forensic evaluation as indicated, further diagnostic steps (imaging studies, ophthalmic examination/funduscopy, laboratory studies, etc.) may be warranted.

PRACTICAL RECOMMENDATIONS

In addition to providing acute medical help, longer-term, multidisciplinary interventions have to be put in place in cases of child abuse. This article summarizes the most important facts pertinent to this subject.