Patient case (clinical description): A 15-year-old boy with mild intellectual disability is brought to the office by his parents for a routine physical examination.  The boy is going to a school for students with learning disabilities.  The patient was adopted, and his immunizations are up to date.  Review of the patient's medical records is notable for cytogenetic studies that showed a small gap near the tip of the long arm of the X chromosome, which is consistent with fragile X syndrome, an X-linked disorder. The defect is an unstable expansion of trinucleotide repeats (CGG) in the fragile X mental retardation 1 (FMR1) gene, located on the long arm of the X chromosome. He is not using any medications and vital signs are within normal levels. His blood chemistry analysis as bellow:
Blood Chemistry Value      Normal Range     Patient Value
Glucose                    90-120 mg/dl     95 mg/dl
BUN (Blood Urea Nitrogen)  7-24 mg/dl       10 mg/dl
Creatinine                 0.7-1.4 mg/dl    0.8 mg/dl
Calcium                    8.5-10.5 mg/dl   9 mg/dl
Sodium                     134-143 mEq/L    135 mEq/L
Potassium                  3.5-4.5 mEq/L    3.7 mEq/L
Chloride                   95-108 mEq/L     98 mEq/L
CO2                        20-30 mEq/L      25 mEq/L
Blood pH                   7.38-7.42        7. 39

Patient's own account: My husband and I brought our 15-year-old son to the clinic for his routine exam. My son is going to school for special needs students. We adopted him a few years ago. His vaccinations are up to date. He already passed some chromosome testing and they found that he has a fragile X syndrome. The doctor told us that it comes from repeats in the fragile X chromosome. My son is not using any medication and his blood pressure temperature and breathing were normal during the exam. He also did a blood test. The results came back and showed that his blood sugar urea creatinine calcium sodium potassium chloride CO2 and blood pH were all within the normal range.

Clinical trial: A Trial of Metformin in Individuals With Fragile X Syndrome

Eligibility criteria:
Inclusion Criteria:

          -  Molecular genetic confirmation of the full FMR1 mutation or mosaicism.

          -  Males and non-pregnant, non-lactating females age 6 to 25 years, inclusive.

          -  Ability of subject and/or caregiver to understand, read, write, and speak English
             fluently to complete study-related materials.

          -  IQ ≤ 79 as measured by the Leiter-III at screening.

          -  Participant is able to speak at least occasional 3-word phrases.

          -  Participant and parent/caregiver are willing to participate in the protocol and able
             to attend the clinic regularly and reliably.

          -  Stable concomitant medication dose and dosing regimen for at least 4 weeks prior to
             the screening/baseline visit, and the intention to maintain a stable regimen of
             allowed concomitant medications for the full duration of the study.

          -  Stable behavioral/educational treatments for at least 4 weeks prior to the
             screening/baseline visit.

          -  Sexually active women of childbearing potential must be using a medically acceptable
             method of birth control for the duration of the study and have a negative urine
             pregnancy test collected at the initial screening/baseline visit.

          -  For participants who are not their own legal guardian, the parent/legal authorized
             representative is able to understand and sign an informed consent to participate in
             the study.

        Exclusion Criteria:

          -  Non-cooperation or inability to follow through with the study protocol.

          -  Life-threatening medical problem or other major systemic illness that compromises
             health or safety and/or would interfere with the study.

          -  History of intolerable adverse events with metformin.

          -  Current or recent metformin treatment (within the past year).

          -  Body mass index (BMI) less than 2 standard deviations for age.

          -  Serum creatinine > 1.4 mg/dl (female) or > 1.5 mg/dl (male) at screening.

          -  History of metabolic acidosis or a condition with lactic acidosis.

          -  Severe B12 deficiency.

          -  Pregnancy at screening or unwillingness to use acceptable method of birth control, if
             applicable.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 6 Years old.
Subject must be at most 25 Years

Eligibility (NLI label): Entailment