A Malabsorption (17) B Birth Weight C Length z-score Milk Protein Intolerance – 10 6 * 4 * Insufficient Intake Protein-losing enteropathy – 2

Celiac Disease – 2 ) 2

Mechanical Feeding Difficulty g

Carbohydrate malabsorption – 1 k

(

Malabsorption Allergic Colitis – 1 t 4 0

e

h

r g

FPIES – 1 o

Genetic Disorder i c

e -2

Genetic Disorders (17) s -

Other organic etiology W

Chromosomal Defects – 9 z h 2 -4 Unknown t

• Angelman’s – 2 r i

• 1p36 deletionIns –u2 fficient Intake B -6 • 7q22 deletion – 1 Mechanical Feeding Diffi0culty -8 n=23 • Mosaic – 1 • DiGeorge Syndrome – 1 IIII MFDD n Organicc r IIII MFDD n Organicc r Malabsorption F o ti e F o ti e i e h ti e h M t n t M n t • Rubinstein-Taybi Syndrome – 1 rp e O rp e O o o s G s G • Williams SyndromeGene –ti1c Disorder b Figure 1: The majority of bpatients had insufficient intake as la NICU % la Single gene – 8 a the cause of their FTT. aOrganic disease made up 24% of cases Other organic etiology M M Total=187 • Schwachman-Diamond Syndrome – 2 ** and is broken down into categories of malabsorption, n=101 • Kabuki SyndromeUnkn –o1wn 100 genetic disorders, andN othero (A). Patients with underlying • Byler’s Disease – 1 genetic disease had significantlyYes lower birth weight (p =

• – 1 0.0364) and were more likely to have a history of NICU

l a

• Greig cephalopolysyndactyly syndrome – 1 t admission (OR 5.96, 95% CI 1.940 - 16.20) than patients with

o t

• ATRX mutation – 1 insufficient intake (B). Length for age at presentation (z- f 50 • o score) also varied significantly by diagnosis (C), but weight n=18 Becker Muscular Dystrophy – 1

Other (11) % and weight for length did not (data not shown). Severe GERD – 3 One-way Analysis of Variance (ANOVA) was used for Pyloric Stenosis – 2 associations between continuous variables and diagnosis. If Leukodystrophy – 1 the one-way ANOVA was statistically significant, post-hoc 0 Total = 187 Pierre-Robin Sequence – 1 pairwise comparisons were performed with correction for IIII MFDD n Organicc r o ti e Septo-Optic Dysplasia – 1 F i e h multiple comparisons using Bonferroni. Pearson’s chi-square Total=187 M t n t rp e O Abusive Head Trauma – 1 o or Fisher’s exact test were used to examine associations NICU stay?s G Neuroendocrine Hyperplasia of Infancy – 1 b between categorical variables and diagnosis la Noa Yes Neuropathic Small Bowel Dysmotility – 1 M * p < 0.05, ** p <0.005