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14q12 Microdeletion Syndrome C4305240

Published: July 22, 2026Updated: August 20, 2026

A rare chromosomal condition where a segment of chromosome 14 is missing. It may cause developmental delays and other health concerns. Treatment is supportive and individualized.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
Q89.9
ICD-11
LA00.0
Body system
congenital
Severity
moderate
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Seizures

Recurrent seizures, often presenting as infantile spasms, which are brief jerking movements that typically occur in clusters.

Seek immediate medical attention if seizures last more than 5 minutes or if there are breathing difficulties during episodes.

!

Congenital heart defects

Structural heart abnormalities such as ventricular septal defects, atrial septal defects, or patent ductus arteriosus.

Cardiac evaluation is essential; seek immediate care if symptoms of heart failure develop such as rapid breathing or poor feeding.

Developmental delay

(neurologic)

Delays in reaching developmental milestones such as sitting, crawling, and walking compared to typical children of the same age.

Frequency: 90-100% of patients

Hypotonia

(neurologic)

Reduced muscle tone resulting in a floppy appearance and difficulty with motor activities such as holding the head up.

Frequency: 80-90% of patients

Failure to thrive

(constitutional)

Poor weight gain and growth velocity, with infants falling below standard growth percentiles for age and sex.

Frequency: 75-85% of patients

Feeding difficulties

(gastrointestinal)

Problems with sucking, swallowing, or accepting solid foods, often requiring specialized feeding techniques or supplements.

Frequency: 70-80% of patients

Speech delay

(neurologic)

Delayed onset of speech and language development, with limited vocabulary and difficulty forming words.

Frequency: 60-70% of patients

Microcephaly

(neurologic)

Abnormally small head circumference present at birth or developing in early infancy due to reduced brain growth.

Frequency: 50-60% of patients

Renal abnormalities

(genitourinary)

Kidney structural issues such as horseshoe kidney, renal hypoplasia, or urinary tract abnormalities detected on imaging.

Frequency: 15-25% of patients

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Healthy lifestyle changes and stress management

Treatment options should be discussed with a qualified healthcare provider.

lifestyle
2

Multidisciplinary Specialist Surveillance

Coordinated care involving neurology, cardiology, and developmental pediatrics for regular assessment of seizures, structural anomalies, and growth patterns.

monitoring
3

Developmental Occupational Therapy

Therapeutic interventions focusing on fine motor skills, self-care abilities, and sensory integration to maximize functional independence.

physical_therapy

Additional treatment options

Seizure Management Protocol

Anticonvulsant medication therapy when seizures are present, selected based on seizure type, with regular efficacy and side effect monitoring.

medication

Behavioral Intervention Program

Structured behavioral modification techniques addressing attention difficulties, repetitive behaviors, and social interaction challenges.

psychological

Structured Environmental Modifications

Creating predictable routines, visual schedules, and sensory-friendly environments to reduce anxiety and support optimal functioning.

lifestyle

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is 14q12 Microdeletion Syndrome C4305240?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Mitter D, Priller C, Kutsche K. FOXG1 syndrome: genotype-phenotype correlation in 201 patients. Mol Syndromol. 2015;6(2):73-84.

review2015View source →
2

Kortüm F, Das S, Flückiger M, et al. The core FOXG1 syndrome phenotype consists of postnatal microcephaly, severe speech delay, absent language, distinctive facial features, and corpus callosum hypoplasia. Am J Med Genet A. 2011;155A(12):3052-3060.

review2011View source →
3

ACMG Board of Directors. Clinical genetics evaluation of identifying autism spectrum disorder associated with single-gene disorders. Genet Med. 2022;24(4):898-911.

4

Bahi-Buisson N, Nectoux J, Girard B, et al. Revisiting the phenotype associated with FOXG1 mutations: two novel cases of congenital Rett variant. Br J Haematol. 2010;148(1):117-124.

review2010View source →
5

Neul JL, Kaufmann WE, Glaze DG, et al. Rett syndrome: revised diagnostic criteria and nomenclature. Ann Neurol. 2010;68(6):944-950.

clinical_trial2010View source →
6

American Academy of Pediatrics Council on Children with Disabilities. Clinical genetics testing in developmental disorders. Pediatrics. 2022;149(1):e2021056035.

position_statement2022View source →
7

Matsumoto N, Takano J, Saitsu H, et al. 14q12 microdeletion syndrome: a case report and review of the literature. J Hum Genet. 2006;51(5):445-450.

review2006View source →
8

GeneReviews. FOXG1-Related Disorder. University of Washington, Seattle. Updated 2023.

9

Sahoo T, Peters SU, Madduri NS, et al. Array CGH detection of cryptic 14q12 deletions: clinical phenotype and molecular characterization. Am J Med Genet A. 2006;140A(18):1934-1941.

review2006View source →
10

International Society of Cytogeneticists. Guidelines for clinical cytogenetics. Cytogenet Genome Res. 2021;161(1-2):1-12.

consensus2021View source →

Medication Comparisons

Compare medications used to treat 14q12 Microdeletion Syndrome C4305240. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy