Rare diseases · Sign or symptom
Failure to thrive
Faltering weight
HP:0001508
What it means
Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.
Although there is no clear consensus on the exact definition of FTT, it is usually diagnoses in a child growing below the 3rd percentile or in a child whose decreased growth has cross two major growth percentiles (for example, from above the 75th percentile to below the 25th percentile).
Rare diseases that can present with this405
Very common80–99%
77- 12q14microdeletion syndrome
- 17p11.2microduplication syndrome
- 19q13.11microdeletion syndrome
- 1p36deletion syndrome
- 2p21microdeletion syndrome
- 3-methylglutaconic aciduria type 1
- 3-methylglutaconic aciduria type 4
- 3-methylglutaconic aciduria type 9
- 46,XY difference of sex development-adrenal insufficiency due to CYP11A1 deficiency
- 6q terminal deletion syndrome
- Acute adrenal insufficiency
- Adams-Oliver syndrome
- Addison disease
- Adrenomyodystrophy
- Alagille syndrome
- Alexander disease
- Alobar holoprosencephaly
- Arginine vasopressin deficiency
- Atypical Werner syndrome
- Autosomal recessive cutis laxa type 2, classic type
- Baraitser-Winter cerebrofrontofacial syndrome
- Barber-Say syndrome
- Cartilage-hair hypoplasia
- Cockayne syndrome type 1
- COG7-CDG
- Complete atrioventricular septal defect
- Congenital bile acid synthesis defect type 1
- Congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
- Congenital lethal erythroderma
- Congenital tufting enteropathy
- Cutaneous mastocytosis-deafness-microtia syndrome
- Cystinosis
- DDOST-CDG
- De Barsy syndrome
- Desmosterolosis
- Developmental delay-language impairment-dopa responsive dystonia-parkinsonism syndrome due to 2q24 microdeletion
- Dyggve-Melchior-Clausen disease
- Early-onset familial hypoaldosteronism
- Ear-patella-short stature syndrome
- Edinburgh malformation syndrome
- Ellis-Van Creveld syndrome
- Erythroderma desquamativum
- Familial glucocorticoid deficiency
- Familial hypoaldosteronism
- Fanconi-Bickel syndrome
- Freeman-Sheldon syndrome
- Fucosidosis
- Glucose-galactose malabsorption
- Glycogen storage disease due to acid maltase deficiency, infantile onset
- Growth delay due to insulin-like growth factor type 1 deficiency
- Haddad syndrome
- Harrod syndrome
- Hawkinsinuria
- Hereditary folate malabsorption
- Hoyeraal-Hreidarsson syndrome
- Hypocalcemic vitamin D-dependent rickets
- Hypohidrotic ectodermal dysplasia with immunodeficiency
- Hypotonia-cystinuria syndrome
- Ichthyosis-intellectual disability-dwarfism-renal impairment syndrome
- Infantile nephropathic cystinosis
- Infantile Refsum disease
- Infantile systemic hyalinosis
- Inherited isolated adrenal insufficiency due to partial CYP11A1 deficiency
- Intellectual disability-seizures-macrocephaly-obesity syndrome
- Intellectual disability-strabismus syndrome
- Isolated biliary atresia
- Isolated complex I deficiency
- Isolated permanent neonatal diabetes mellitus
- Johanson-Blizzard syndrome
- Late-onset isolated ACTH deficiency
- Leukocyte adhesion deficiency type II
- Lipodystrophy-intellectual disability-deafness syndrome
- Lysinuric protein intolerance
- Marden-Walker syndrome
- Marshall-Smith syndrome
- Maternal uniparental disomy of chromosome 9 syndrome
- Melorheostosis
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: FTT · Poor weight gain · Postnatal failure to thrive · Undergrowth · Weight faltering
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.